diff --git a/.github/workflows/Bundle.yml b/.github/workflows/Bundle.yml
index 665ead2577..ff2c46bcec 100644
--- a/.github/workflows/Bundle.yml
+++ b/.github/workflows/Bundle.yml
@@ -13,7 +13,7 @@ on:
             - release
 
 concurrency:
-    group: bundle
+    group: bundle-${{ github.ref }}
     cancel-in-progress: false
 
 jobs:
diff --git a/.github/workflows/FrontendTest.yml b/.github/workflows/FrontendTest.yml
index a9b5d55961..07e6cf55da 100644
--- a/.github/workflows/FrontendTest.yml
+++ b/.github/workflows/FrontendTest.yml
@@ -63,17 +63,19 @@ jobs:
             - name: Run tests
               working-directory: ./test/frontend
               run: |
-                  julia -e "import Pkg; Pkg.add(path=\"$GITHUB_WORKSPACE\"); Pkg.instantiate(); import Pluto; Pluto.run(port=$PLUTO_PORT, require_secret_for_access=false)" & # Run Pluto.jl server in the background
+                julia --project=$GITHUB_WORKSPACE -e 'import Pluto
+                  # Run Pluto.jl server in the background
+                  options = Pluto.Configuration.from_flat_kwargs(; 
+                    port=parse(Int, ENV["PLUTO_PORT"]), 
+                    require_secret_for_access=false,
+                  )
+                  🍭 = Pluto.ServerSession(; options)
+                  server = Pluto.run!(🍭)
 
-                  # Wait for Pluto to initialize
-                  TIMES_TRIED=0
-                  until [ $TIMES_TRIED -eq 60 ] || $(curl --output /dev/null --silent --fail "http://localhost:$PLUTO_PORT/"); do
-                      printf '.'
-                      TIMES_TRIED=$((TIMES_TRIED+1))
-                      sleep 1
-                  done
+                  run(`npm run test`)
+                  
+                  close(server)'
 
-                  npm run test
               env:
                   PLUTO_PORT: 1235
                   PLUTO_TEST_OFFLINE: ${{ github.ref_name == 'release' }}
diff --git a/.github/workflows/Test.yml b/.github/workflows/Test.yml
index 37e73f3784..27443f0c5a 100644
--- a/.github/workflows/Test.yml
+++ b/.github/workflows/Test.yml
@@ -27,14 +27,14 @@ on:
 jobs:
     test:
         runs-on: ${{ matrix.os }}
-        timeout-minutes: 40
+        timeout-minutes: 50
 
         strategy:
             # Without setting this, a failing test cancels all others
             fail-fast: false
             matrix:
                 # We test quite a lot of versions because we do some OS and version specific things unfortunately
-                julia-version: ["1.6", "1.7", "1.8", "1.9"] #, "nightly"]
+                julia-version: ["1.6", "1.8", "1.9", "~1.10.0-0"]
                 os: [ubuntu-latest, macOS-latest, windows-latest]
 
         steps:
diff --git a/.github/workflows/TypeScriptCheck.yml b/.github/workflows/TypeScriptCheck.yml
index d4830bc6c8..bf8b115bc2 100644
--- a/.github/workflows/TypeScriptCheck.yml
+++ b/.github/workflows/TypeScriptCheck.yml
@@ -26,7 +26,7 @@ jobs:
         with:
           node-version: "18.x"
 
-      - run: npm install typescript -g
+      - run: npm install typescript@5.0.4 -g
       
       - run: npm install
         working-directory: frontend
diff --git a/Project.toml b/Project.toml
index 29c146fc70..7292cf6847 100644
--- a/Project.toml
+++ b/Project.toml
@@ -2,13 +2,12 @@ name = "Pluto"
 uuid = "c3e4b0f8-55cb-11ea-2926-15256bba5781"
 license = "MIT"
 authors = ["Fons van der Plas <fons@plutojl.org>"]
-version = "0.19.25"
+version = "0.19.27"
 
 [deps]
 Base64 = "2a0f44e3-6c83-55bd-87e4-b1978d98bd5f"
 Configurations = "5218b696-f38b-4ac9-8b61-a12ec717816d"
 Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"
-Distributed = "8ba89e20-285c-5b6f-9357-94700520ee1b"
 FileWatching = "7b1f6079-737a-58dc-b8bc-7a2ca5c1b5ee"
 FuzzyCompletions = "fb4132e2-a121-4a70-b8a1-d5b831dcdcc2"
 HTTP = "cd3eb016-35fb-5094-929b-558a96fad6f3"
@@ -17,6 +16,7 @@ InteractiveUtils = "b77e0a4c-d291-57a0-90e8-8db25a27a240"
 Logging = "56ddb016-857b-54e1-b83d-db4d58db5568"
 LoggingExtras = "e6f89c97-d47a-5376-807f-9c37f3926c36"
 MIMEs = "6c6e2e6c-3030-632d-7369-2d6c69616d65"
+Malt = "36869731-bdee-424d-aa32-cab38c994e3b"
 Markdown = "d6f4376e-aef5-505a-96c1-9c027394607a"
 MsgPack = "99f44e22-a591-53d1-9472-aa23ef4bd671"
 Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
@@ -25,6 +25,7 @@ PrecompileTools = "aea7be01-6a6a-4083-8856-8a6e6704d82a"
 REPL = "3fa0cd96-eef1-5676-8a61-b3b8758bbffb"
 RegistryInstances = "2792f1a3-b283-48e8-9a74-f99dce5104f3"
 RelocatableFolders = "05181044-ff0b-4ac5-8273-598c1e38db00"
+Scratch = "6c6a2e73-6563-6170-7368-637461726353"
 Sockets = "6462fe0b-24de-5631-8697-dd941f90decc"
 TOML = "fa267f1f-6049-4f14-aa54-33bafae1ed76"
 Tables = "bd369af6-aec1-5ad0-b16a-f7cc5008161c"
@@ -38,11 +39,13 @@ HTTP = "^1.5.2"
 HypertextLiteral = "0.7, 0.8, 0.9"
 LoggingExtras = "0.4, 1"
 MIMEs = "0.1"
+Malt = "1.0.3"
 MsgPack = "1.1"
 PrecompileSignatures = "3"
 PrecompileTools = "1"
 RegistryInstances = "0.1"
 RelocatableFolders = "0.1, 0.2, 0.3, 1"
+Scratch = "1.1"
 Tables = "1"
 URIs = "1.3"
 julia = "^1.6"
diff --git a/frontend-bundler/package-lock.json b/frontend-bundler/package-lock.json
index ee443a186a..a9b30f6cff 100644
--- a/frontend-bundler/package-lock.json
+++ b/frontend-bundler/package-lock.json
@@ -76,9 +76,9 @@
             }
         },
         "node_modules/@babel/core/node_modules/semver": {
-            "version": "6.3.0",
-            "resolved": "https://registry.npmjs.org/semver/-/semver-6.3.0.tgz",
-            "integrity": "sha512-b39TBaTSfV6yBrapU89p5fKekE2m/NwnDocOVruQFS1/veMgdzuPcnOM34M6CwxW8jH/lxEa5rBoDeUwu5HHTw==",
+            "version": "6.3.1",
+            "resolved": "https://registry.npmjs.org/semver/-/semver-6.3.1.tgz",
+            "integrity": "sha512-BR7VvDCVHO+q2xBEWskxS6DJE1qRnb7DxzUrogb71CWoSficBxYsiAGd+Kl0mmq/MprG9yArRkyrQxTO6XjMzA==",
             "bin": {
                 "semver": "bin/semver.js"
             }
@@ -114,9 +114,9 @@
             }
         },
         "node_modules/@babel/helper-compilation-targets/node_modules/semver": {
-            "version": "6.3.0",
-            "resolved": "https://registry.npmjs.org/semver/-/semver-6.3.0.tgz",
-            "integrity": "sha512-b39TBaTSfV6yBrapU89p5fKekE2m/NwnDocOVruQFS1/veMgdzuPcnOM34M6CwxW8jH/lxEa5rBoDeUwu5HHTw==",
+            "version": "6.3.1",
+            "resolved": "https://registry.npmjs.org/semver/-/semver-6.3.1.tgz",
+            "integrity": "sha512-BR7VvDCVHO+q2xBEWskxS6DJE1qRnb7DxzUrogb71CWoSficBxYsiAGd+Kl0mmq/MprG9yArRkyrQxTO6XjMzA==",
             "bin": {
                 "semver": "bin/semver.js"
             }
@@ -385,6 +385,58 @@
                 "node": ">=6.9.0"
             }
         },
+        "node_modules/@jridgewell/gen-mapping": {
+            "version": "0.3.2",
+            "resolved": "https://registry.npmjs.org/@jridgewell/gen-mapping/-/gen-mapping-0.3.2.tgz",
+            "integrity": "sha512-mh65xKQAzI6iBcFzwv28KVWSmCkdRBWoOh+bYQGW3+6OZvbbN3TqMGo5hqYxQniRcH9F2VZIoJCm4pa3BPDK/A==",
+            "dependencies": {
+                "@jridgewell/set-array": "^1.0.1",
+                "@jridgewell/sourcemap-codec": "^1.4.10",
+                "@jridgewell/trace-mapping": "^0.3.9"
+            },
+            "engines": {
+                "node": ">=6.0.0"
+            }
+        },
+        "node_modules/@jridgewell/resolve-uri": {
+            "version": "3.1.0",
+            "resolved": "https://registry.npmjs.org/@jridgewell/resolve-uri/-/resolve-uri-3.1.0.tgz",
+            "integrity": "sha512-F2msla3tad+Mfht5cJq7LSXcdudKTWCVYUgw6pLFOOHSTtZlj6SWNYAp+AhuqLmWdBO2X5hPrLcu8cVP8fy28w==",
+            "engines": {
+                "node": ">=6.0.0"
+            }
+        },
+        "node_modules/@jridgewell/set-array": {
+            "version": "1.1.2",
+            "resolved": "https://registry.npmjs.org/@jridgewell/set-array/-/set-array-1.1.2.tgz",
+            "integrity": "sha512-xnkseuNADM0gt2bs+BvhO0p78Mk762YnZdsuzFV018NoG1Sj1SCQvpSqa7XUaTam5vAGasABV9qXASMKnFMwMw==",
+            "engines": {
+                "node": ">=6.0.0"
+            }
+        },
+        "node_modules/@jridgewell/source-map": {
+            "version": "0.3.2",
+            "resolved": "https://registry.npmjs.org/@jridgewell/source-map/-/source-map-0.3.2.tgz",
+            "integrity": "sha512-m7O9o2uR8k2ObDysZYzdfhb08VuEml5oWGiosa1VdaPZ/A6QyPkAJuwN0Q1lhULOf6B7MtQmHENS743hWtCrgw==",
+            "dependencies": {
+                "@jridgewell/gen-mapping": "^0.3.0",
+                "@jridgewell/trace-mapping": "^0.3.9"
+            }
+        },
+        "node_modules/@jridgewell/sourcemap-codec": {
+            "version": "1.4.14",
+            "resolved": "https://registry.npmjs.org/@jridgewell/sourcemap-codec/-/sourcemap-codec-1.4.14.tgz",
+            "integrity": "sha512-XPSJHWmi394fuUuzDnGz1wiKqWfo1yXecHQMRf2l6hztTO+nPru658AyDngaBe7isIxEkRsPR3FZh+s7iVa4Uw=="
+        },
+        "node_modules/@jridgewell/trace-mapping": {
+            "version": "0.3.14",
+            "resolved": "https://registry.npmjs.org/@jridgewell/trace-mapping/-/trace-mapping-0.3.14.tgz",
+            "integrity": "sha512-bJWEfQ9lPTvm3SneWwRFVLzrh6nhjwqw7TUFFBEMzwvg7t7PCDenf2lDwqo4NQXzdpgBXyFgDWnQA+2vkruksQ==",
+            "dependencies": {
+                "@jridgewell/resolve-uri": "^3.0.3",
+                "@jridgewell/sourcemap-codec": "^1.4.10"
+            }
+        },
         "node_modules/@lezer/common": {
             "version": "0.15.12",
             "resolved": "https://registry.npmjs.org/@lezer/common/-/common-0.15.12.tgz",
@@ -6096,9 +6148,9 @@
             }
         },
         "node_modules/semver": {
-            "version": "5.7.1",
-            "resolved": "https://registry.npmjs.org/semver/-/semver-5.7.1.tgz",
-            "integrity": "sha512-sauaDf/PZdVgrLTNYHRtpXa1iRiKcaebiKQ1BJdpQlWH2lCvexQdX55snPFyK7QzpudqbCI0qXFfOasHdyNDGQ==",
+            "version": "5.7.2",
+            "resolved": "https://registry.npmjs.org/semver/-/semver-5.7.2.tgz",
+            "integrity": "sha512-cBznnQ9KjJqU67B52RMC65CMarK2600WFnbkcaiwWq3xy/5haFJlshgnpjovMVJ+Hff49d8GEn0b87C5pDQ10g==",
             "bin": {
                 "semver": "bin/semver"
             }
@@ -6427,12 +6479,13 @@
             }
         },
         "node_modules/terser": {
-            "version": "5.9.0",
-            "resolved": "https://registry.npmjs.org/terser/-/terser-5.9.0.tgz",
-            "integrity": "sha512-h5hxa23sCdpzcye/7b8YqbE5OwKca/ni0RQz1uRX3tGh8haaGHqcuSqbGRybuAKNdntZ0mDgFNXPJ48xQ2RXKQ==",
+            "version": "5.14.2",
+            "resolved": "https://registry.npmjs.org/terser/-/terser-5.14.2.tgz",
+            "integrity": "sha512-oL0rGeM/WFQCUd0y2QrWxYnq7tfSuKBiqTjRPWrRgB46WD/kiwHwF8T23z78H6Q6kGCuuHcPB+KULHRdxvVGQA==",
             "dependencies": {
+                "@jridgewell/source-map": "^0.3.2",
+                "acorn": "^8.5.0",
                 "commander": "^2.20.0",
-                "source-map": "~0.7.2",
                 "source-map-support": "~0.5.20"
             },
             "bin": {
@@ -6442,19 +6495,22 @@
                 "node": ">=10"
             }
         },
+        "node_modules/terser/node_modules/acorn": {
+            "version": "8.7.1",
+            "resolved": "https://registry.npmjs.org/acorn/-/acorn-8.7.1.tgz",
+            "integrity": "sha512-Xx54uLJQZ19lKygFXOWsscKUbsBZW0CPykPhVQdhIeIwrbPmJzqeASDInc8nKBnp/JT6igTs82qPXz069H8I/A==",
+            "bin": {
+                "acorn": "bin/acorn"
+            },
+            "engines": {
+                "node": ">=0.4.0"
+            }
+        },
         "node_modules/terser/node_modules/commander": {
             "version": "2.20.3",
             "resolved": "https://registry.npmjs.org/commander/-/commander-2.20.3.tgz",
             "integrity": "sha512-GpVkmM8vF2vQUkj2LvZmD35JxeJOLCwJ9cUkugyk2nuhbv3+mJvpLYYt+0+USMxE+oj+ey/lJEnhZw75x/OMcQ=="
         },
-        "node_modules/terser/node_modules/source-map": {
-            "version": "0.7.3",
-            "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.7.3.tgz",
-            "integrity": "sha512-CkCj6giN3S+n9qrYiBTX5gystlENnRW5jZeNLHpe6aue+SrHcG5VYwujhW9s4dY31mEGsxBDrHR6oI69fTXsaQ==",
-            "engines": {
-                "node": ">= 8"
-            }
-        },
         "node_modules/timers-browserify": {
             "version": "2.0.12",
             "resolved": "https://registry.npmjs.org/timers-browserify/-/timers-browserify-2.0.12.tgz",
@@ -6874,9 +6930,9 @@
             }
         },
         "node_modules/word-wrap": {
-            "version": "1.2.3",
-            "resolved": "https://registry.npmjs.org/word-wrap/-/word-wrap-1.2.3.tgz",
-            "integrity": "sha512-Hz/mrNwitNRh/HUAtM/VT/5VH+ygD6DV7mYKZAtHOrbs8U7lvPS6xf7EJKMF0uW1KJCl0H701g3ZGus+muE5vQ==",
+            "version": "1.2.4",
+            "resolved": "https://registry.npmjs.org/word-wrap/-/word-wrap-1.2.4.tgz",
+            "integrity": "sha512-2V81OA4ugVo5pRo46hAoD2ivUJx8jXmWXfUkY4KFNw0hEptvN0QfH3K4nHiwzGeKl5rFKedV48QVoqYavy4YpA==",
             "engines": {
                 "node": ">=0.10.0"
             }
@@ -7079,9 +7135,9 @@
             },
             "dependencies": {
                 "semver": {
-                    "version": "6.3.0",
-                    "resolved": "https://registry.npmjs.org/semver/-/semver-6.3.0.tgz",
-                    "integrity": "sha512-b39TBaTSfV6yBrapU89p5fKekE2m/NwnDocOVruQFS1/veMgdzuPcnOM34M6CwxW8jH/lxEa5rBoDeUwu5HHTw=="
+                    "version": "6.3.1",
+                    "resolved": "https://registry.npmjs.org/semver/-/semver-6.3.1.tgz",
+                    "integrity": "sha512-BR7VvDCVHO+q2xBEWskxS6DJE1qRnb7DxzUrogb71CWoSficBxYsiAGd+Kl0mmq/MprG9yArRkyrQxTO6XjMzA=="
                 }
             }
         },
@@ -7107,9 +7163,9 @@
             },
             "dependencies": {
                 "semver": {
-                    "version": "6.3.0",
-                    "resolved": "https://registry.npmjs.org/semver/-/semver-6.3.0.tgz",
-                    "integrity": "sha512-b39TBaTSfV6yBrapU89p5fKekE2m/NwnDocOVruQFS1/veMgdzuPcnOM34M6CwxW8jH/lxEa5rBoDeUwu5HHTw=="
+                    "version": "6.3.1",
+                    "resolved": "https://registry.npmjs.org/semver/-/semver-6.3.1.tgz",
+                    "integrity": "sha512-BR7VvDCVHO+q2xBEWskxS6DJE1qRnb7DxzUrogb71CWoSficBxYsiAGd+Kl0mmq/MprG9yArRkyrQxTO6XjMzA=="
                 }
             }
         },
@@ -7304,6 +7360,49 @@
                 "to-fast-properties": "^2.0.0"
             }
         },
+        "@jridgewell/gen-mapping": {
+            "version": "0.3.2",
+            "resolved": "https://registry.npmjs.org/@jridgewell/gen-mapping/-/gen-mapping-0.3.2.tgz",
+            "integrity": "sha512-mh65xKQAzI6iBcFzwv28KVWSmCkdRBWoOh+bYQGW3+6OZvbbN3TqMGo5hqYxQniRcH9F2VZIoJCm4pa3BPDK/A==",
+            "requires": {
+                "@jridgewell/set-array": "^1.0.1",
+                "@jridgewell/sourcemap-codec": "^1.4.10",
+                "@jridgewell/trace-mapping": "^0.3.9"
+            }
+        },
+        "@jridgewell/resolve-uri": {
+            "version": "3.1.0",
+            "resolved": "https://registry.npmjs.org/@jridgewell/resolve-uri/-/resolve-uri-3.1.0.tgz",
+            "integrity": "sha512-F2msla3tad+Mfht5cJq7LSXcdudKTWCVYUgw6pLFOOHSTtZlj6SWNYAp+AhuqLmWdBO2X5hPrLcu8cVP8fy28w=="
+        },
+        "@jridgewell/set-array": {
+            "version": "1.1.2",
+            "resolved": "https://registry.npmjs.org/@jridgewell/set-array/-/set-array-1.1.2.tgz",
+            "integrity": "sha512-xnkseuNADM0gt2bs+BvhO0p78Mk762YnZdsuzFV018NoG1Sj1SCQvpSqa7XUaTam5vAGasABV9qXASMKnFMwMw=="
+        },
+        "@jridgewell/source-map": {
+            "version": "0.3.2",
+            "resolved": "https://registry.npmjs.org/@jridgewell/source-map/-/source-map-0.3.2.tgz",
+            "integrity": "sha512-m7O9o2uR8k2ObDysZYzdfhb08VuEml5oWGiosa1VdaPZ/A6QyPkAJuwN0Q1lhULOf6B7MtQmHENS743hWtCrgw==",
+            "requires": {
+                "@jridgewell/gen-mapping": "^0.3.0",
+                "@jridgewell/trace-mapping": "^0.3.9"
+            }
+        },
+        "@jridgewell/sourcemap-codec": {
+            "version": "1.4.14",
+            "resolved": "https://registry.npmjs.org/@jridgewell/sourcemap-codec/-/sourcemap-codec-1.4.14.tgz",
+            "integrity": "sha512-XPSJHWmi394fuUuzDnGz1wiKqWfo1yXecHQMRf2l6hztTO+nPru658AyDngaBe7isIxEkRsPR3FZh+s7iVa4Uw=="
+        },
+        "@jridgewell/trace-mapping": {
+            "version": "0.3.14",
+            "resolved": "https://registry.npmjs.org/@jridgewell/trace-mapping/-/trace-mapping-0.3.14.tgz",
+            "integrity": "sha512-bJWEfQ9lPTvm3SneWwRFVLzrh6nhjwqw7TUFFBEMzwvg7t7PCDenf2lDwqo4NQXzdpgBXyFgDWnQA+2vkruksQ==",
+            "requires": {
+                "@jridgewell/resolve-uri": "^3.0.3",
+                "@jridgewell/sourcemap-codec": "^1.4.10"
+            }
+        },
         "@lezer/common": {
             "version": "0.15.12",
             "resolved": "https://registry.npmjs.org/@lezer/common/-/common-0.15.12.tgz",
@@ -11364,9 +11463,9 @@
             }
         },
         "semver": {
-            "version": "5.7.1",
-            "resolved": "https://registry.npmjs.org/semver/-/semver-5.7.1.tgz",
-            "integrity": "sha512-sauaDf/PZdVgrLTNYHRtpXa1iRiKcaebiKQ1BJdpQlWH2lCvexQdX55snPFyK7QzpudqbCI0qXFfOasHdyNDGQ=="
+            "version": "5.7.2",
+            "resolved": "https://registry.npmjs.org/semver/-/semver-5.7.2.tgz",
+            "integrity": "sha512-cBznnQ9KjJqU67B52RMC65CMarK2600WFnbkcaiwWq3xy/5haFJlshgnpjovMVJ+Hff49d8GEn0b87C5pDQ10g=="
         },
         "serve-handler": {
             "version": "6.1.5",
@@ -11618,24 +11717,25 @@
             "integrity": "sha512-wK0Ri4fOGjv/XPy8SBHZChl8CM7uMc5VML7SqiQ0zG7+J5Vr+RMQDoHa2CNT6KHUnTGIXH34UDMkPzAUyapBZg=="
         },
         "terser": {
-            "version": "5.9.0",
-            "resolved": "https://registry.npmjs.org/terser/-/terser-5.9.0.tgz",
-            "integrity": "sha512-h5hxa23sCdpzcye/7b8YqbE5OwKca/ni0RQz1uRX3tGh8haaGHqcuSqbGRybuAKNdntZ0mDgFNXPJ48xQ2RXKQ==",
+            "version": "5.14.2",
+            "resolved": "https://registry.npmjs.org/terser/-/terser-5.14.2.tgz",
+            "integrity": "sha512-oL0rGeM/WFQCUd0y2QrWxYnq7tfSuKBiqTjRPWrRgB46WD/kiwHwF8T23z78H6Q6kGCuuHcPB+KULHRdxvVGQA==",
             "requires": {
+                "@jridgewell/source-map": "^0.3.2",
+                "acorn": "^8.5.0",
                 "commander": "^2.20.0",
-                "source-map": "~0.7.2",
                 "source-map-support": "~0.5.20"
             },
             "dependencies": {
+                "acorn": {
+                    "version": "8.7.1",
+                    "resolved": "https://registry.npmjs.org/acorn/-/acorn-8.7.1.tgz",
+                    "integrity": "sha512-Xx54uLJQZ19lKygFXOWsscKUbsBZW0CPykPhVQdhIeIwrbPmJzqeASDInc8nKBnp/JT6igTs82qPXz069H8I/A=="
+                },
                 "commander": {
                     "version": "2.20.3",
                     "resolved": "https://registry.npmjs.org/commander/-/commander-2.20.3.tgz",
                     "integrity": "sha512-GpVkmM8vF2vQUkj2LvZmD35JxeJOLCwJ9cUkugyk2nuhbv3+mJvpLYYt+0+USMxE+oj+ey/lJEnhZw75x/OMcQ=="
-                },
-                "source-map": {
-                    "version": "0.7.3",
-                    "resolved": "https://registry.npmjs.org/source-map/-/source-map-0.7.3.tgz",
-                    "integrity": "sha512-CkCj6giN3S+n9qrYiBTX5gystlENnRW5jZeNLHpe6aue+SrHcG5VYwujhW9s4dY31mEGsxBDrHR6oI69fTXsaQ=="
                 }
             }
         },
@@ -11986,9 +12086,9 @@
             }
         },
         "word-wrap": {
-            "version": "1.2.3",
-            "resolved": "https://registry.npmjs.org/word-wrap/-/word-wrap-1.2.3.tgz",
-            "integrity": "sha512-Hz/mrNwitNRh/HUAtM/VT/5VH+ygD6DV7mYKZAtHOrbs8U7lvPS6xf7EJKMF0uW1KJCl0H701g3ZGus+muE5vQ=="
+            "version": "1.2.4",
+            "resolved": "https://registry.npmjs.org/word-wrap/-/word-wrap-1.2.4.tgz",
+            "integrity": "sha512-2V81OA4ugVo5pRo46hAoD2ivUJx8jXmWXfUkY4KFNw0hEptvN0QfH3K4nHiwzGeKl5rFKedV48QVoqYavy4YpA=="
         },
         "wrap-ansi": {
             "version": "7.0.0",
diff --git a/frontend/common/PlutoConnection.js b/frontend/common/PlutoConnection.js
index b4c336a04d..4e6fa5660a 100644
--- a/frontend/common/PlutoConnection.js
+++ b/frontend/common/PlutoConnection.js
@@ -265,7 +265,7 @@ const default_ws_address = () => ws_address_from_base(window.location.href)
  * @param {{
  *  on_unrequested_update: (message: PlutoMessage, by_me: boolean) => void,
  *  on_reconnect: () => boolean,
- *  on_connection_status: (connection_status: boolean) => void,
+ *  on_connection_status: (connection_status: boolean, hopeless: boolean) => void,
  *  connect_metadata?: Object,
  *  ws_address?: String,
  * }} options
@@ -364,7 +364,7 @@ export const create_pluto_connection = async ({
                     on_unrequested_update(update, by_me)
                 },
                 on_socket_close: async () => {
-                    on_connection_status(false)
+                    on_connection_status(false, false)
 
                     console.log(`Starting new websocket`, new Date().toLocaleTimeString())
                     await Promises.delay(reconnect_after_close_delay)
@@ -373,7 +373,7 @@ export const create_pluto_connection = async ({
                     console.log(`Starting state sync`, new Date().toLocaleTimeString())
                     const accept = on_reconnect()
                     console.log(`State sync ${accept ? "" : "not "}successful`, new Date().toLocaleTimeString())
-                    on_connection_status(accept)
+                    on_connection_status(accept, false)
                     if (!accept) {
                         alert("Connection out of sync 😥\n\nRefresh the page to continue")
                     }
@@ -394,14 +394,10 @@ export const create_pluto_connection = async ({
             console.log("Client object: ", client)
 
             if (connect_metadata.notebook_id != null && !u.message.notebook_exists) {
-                // https://github.com/fonsp/Pluto.jl/issues/55
-                if (confirm("A new server was started - this notebook session is no longer running.\n\nWould you like to go back to the main menu?")) {
-                    window.location.href = "./"
-                }
-                on_connection_status(false)
+                on_connection_status(false, true)
                 return {}
             }
-            on_connection_status(true)
+            on_connection_status(true, false)
 
             const ping = () => {
                 send("ping", {}, {})
diff --git a/frontend/common/SliderServerClient.js b/frontend/common/SliderServerClient.js
index 49e64ffb19..f93f46efd3 100644
--- a/frontend/common/SliderServerClient.js
+++ b/frontend/common/SliderServerClient.js
@@ -8,6 +8,23 @@ const assert_response_ok = (/** @type {Response} */ r) => (r.ok ? r : Promise.re
 
 const actions_to_keep = ["get_published_object"]
 
+const get_start = (graph, v) => Object.values(graph).find((node) => Object.keys(node.downstream_cells_map).includes(v))?.cell_id
+const get_starts = (graph, vars) => new Set([...vars].map((v) => get_start(graph, v)))
+const recursive_dependencies = (graph, starts) => {
+    const deps = new Set(starts)
+    const ends = [...starts]
+    while (ends.length > 0) {
+        const node = ends.splice(0, 1)[0]
+        _.flatten(Object.values(graph[node].downstream_cells_map)).forEach((child) => {
+            if (!deps.has(child)) {
+                ends.push(child)
+                deps.add(child)
+            }
+        })
+    }
+    return deps
+}
+
 export const nothing_actions = ({ actions }) =>
     Object.fromEntries(
         Object.entries(actions).map(([k, v]) => [
@@ -23,6 +40,12 @@ export const nothing_actions = ({ actions }) =>
     )
 
 export const slider_server_actions = ({ setStatePromise, launch_params, actions, get_original_state, get_current_state, apply_notebook_patches }) => {
+    setStatePromise(
+        immer((state) => {
+            state.slider_server.connecting = true
+        })
+    )
+
     const notebookfile_hash = fetch(new Request(launch_params.notebookfile, { integrity: launch_params.notebookfile_integrity }))
         .then(assert_response_ok)
         .then((r) => r.arrayBuffer())
@@ -36,7 +59,15 @@ export const slider_server_actions = ({ setStatePromise, launch_params, actions,
         .then((r) => r.arrayBuffer())
         .then((b) => unpack(new Uint8Array(b)))
 
-    bond_connections.then((x) => console.log("Bond connections:", x))
+    bond_connections.then((x) => {
+        console.log("Bond connections:", x)
+        setStatePromise(
+            immer((state) => {
+                state.slider_server.connecting = false
+                state.slider_server.interactive = Object.keys(x).length > 0
+            })
+        )
+    })
 
     const mybonds = {}
     const bonds_to_set = {
@@ -47,6 +78,20 @@ export const slider_server_actions = ({ setStatePromise, launch_params, actions,
         const hash = await notebookfile_hash
         const graph = await bond_connections
 
+        // compute dependencies and update cell running statuses
+        const dep_graph = get_current_state().cell_dependencies
+        const starts = get_starts(dep_graph, bonds_to_set.current)
+        const running_cells = [...recursive_dependencies(dep_graph, starts)]
+
+        const update_cells_running = async (running) =>
+            await setStatePromise(
+                immer((state) => {
+                    running_cells.forEach((cell_id) => (state.notebook.cell_results[cell_id][starts.has(cell_id) ? "running" : "queued"] = running))
+                })
+            )
+
+        await update_cells_running(true)
+
         if (bonds_to_set.current.size > 0) {
             const to_send = new Set(bonds_to_set.current)
             bonds_to_set.current.forEach((varname) => (graph[varname] ?? []).forEach((x) => to_send.add(x)))
@@ -92,6 +137,9 @@ export const slider_server_actions = ({ setStatePromise, launch_params, actions,
                 )
             } catch (e) {
                 console.error(unpacked, e)
+            } finally {
+                // reset cell running state regardless of request outcome
+                await update_cells_running(false)
             }
         }
     })
diff --git a/frontend/components/Cell.js b/frontend/components/Cell.js
index 618964b72b..dea158dc5f 100644
--- a/frontend/components/Cell.js
+++ b/frontend/components/Cell.js
@@ -136,7 +136,31 @@ export const Cell = ({
     const remount = useMemo(() => () => setKey(key + 1))
     // cm_forced_focus is null, except when a line needs to be highlighted because it is part of a stack trace
     const [cm_forced_focus, set_cm_forced_focus] = useState(/** @type{any} */ (null))
+    const [cm_highlighted_range, set_cm_highlighted_range] = useState(null)
     const [cm_highlighted_line, set_cm_highlighted_line] = useState(null)
+    const [cm_diagnostics, set_cm_diagnostics] = useState([])
+
+    useEffect(() => {
+        const diagnosticListener = (e) => {
+            if (e.detail.cell_id === cell_id) {
+                set_cm_diagnostics(e.detail.diagnostics)
+            }
+        }
+        window.addEventListener("cell_diagnostics", diagnosticListener)
+        return () => window.removeEventListener("cell_diagnostics", diagnosticListener)
+    }, [cell_id])
+
+    useEffect(() => {
+        const highlightRangeListener = (e) => {
+            if (e.detail.cell_id == cell_id && e.detail.from != null && e.detail.to != null) {
+                set_cm_highlighted_range({ from: e.detail.from, to: e.detail.to })
+            } else {
+                set_cm_highlighted_range(null)
+            }
+        }
+        window.addEventListener("cell_highlight_range", highlightRangeListener)
+        return () => window.removeEventListener("cell_highlight_range", highlightRangeListener)
+    }, [cell_id])
 
     useEffect(() => {
         const focusListener = (e) => {
@@ -278,7 +302,7 @@ export const Cell = ({
                     pluto_actions.add_remote_cell(cell_id, "before")
                 }}
                 class="add_cell before"
-                title="Add cell"
+                title="Add cell (Ctrl + Enter)"
             >
                 <span></span>
             </button>
@@ -309,10 +333,13 @@ export const Cell = ({
                 set_show_logs=${set_show_logs}
                 set_cell_disabled=${set_cell_disabled}
                 cm_highlighted_line=${cm_highlighted_line}
-                set_cm_highlighted_line=${set_cm_highlighted_line}
+                cm_highlighted_range=${cm_highlighted_range}
+                cm_diagnostics=${cm_diagnostics}
                 onerror=${remount}
             />
-            ${show_logs ? html`<${Logs} logs=${Object.values(logs)} line_heights=${line_heights} set_cm_highlighted_line=${set_cm_highlighted_line} />` : null}
+            ${show_logs && cell_api_ready
+                ? html`<${Logs} logs=${Object.values(logs)} line_heights=${line_heights} set_cm_highlighted_line=${set_cm_highlighted_line} />`
+                : null}
             <${RunArea}
                 cell_id=${cell_id}
                 running_disabled=${running_disabled}
@@ -333,7 +360,7 @@ export const Cell = ({
                     pluto_actions.add_remote_cell(cell_id, "after")
                 }}
                 class="add_cell after"
-                title="Add cell"
+                title="Add cell (Ctrl + Enter)"
             >
                 <span></span>
             </button>
@@ -386,8 +413,10 @@ export const IsolatedCell = ({ cell_input: { cell_id, metadata }, cell_result: {
 
     return html`
         <pluto-cell ref=${node_ref} id=${cell_id} class=${hidden ? "hidden-cell" : "isolated-cell"}>
-            ${cell_api_ready ? html`<${CellOutput} ...${output} sanitize_html=${sanitize_html} cell_id=${cell_id} />` : html``}
-            ${show_logs ? html`<${Logs} logs=${Object.values(logs)} line_heights=${[15]} set_cm_highlighted_line=${() => {}} />` : null}
+            <<<<<<< HEAD ${cell_api_ready ? html`<${CellOutput} ...${output} sanitize_html=${sanitize_html} cell_id=${cell_id} />` : html``}
+            ${show_logs ? html`<${Logs} logs=${Object.values(logs)} line_heights=${[15]} set_cm_highlighted_line=${() => {}} />` : null} =======
+            ${cell_api_ready ? html`<${CellOutput} ...${output} cell_id=${cell_id} />` : html``}
+            ${show_logs ? html`<${Logs} logs=${Object.values(logs)} line_heights=${[15]} set_cm_highlighted_line=${() => {}} />` : null} >>>>>>> main
         </pluto-cell>
     `
 }
diff --git a/frontend/components/CellInput.js b/frontend/components/CellInput.js
index e3a57c6421..247775d413 100644
--- a/frontend/components/CellInput.js
+++ b/frontend/components/CellInput.js
@@ -48,6 +48,7 @@ import {
     pythonLanguage,
     syntaxHighlighting,
     cssLanguage,
+    setDiagnostics,
 } from "../imports/CodemirrorPlutoSetup.js"
 
 import { markdown, html as htmlLang, javascript, sqlLang, python, julia_mixed } from "./CellInput/mixedParsers.js"
@@ -59,7 +60,7 @@ import { cell_movement_plugin, prevent_holding_a_key_from_doing_things_across_ce
 import { pluto_paste_plugin } from "./CellInput/pluto_paste_plugin.js"
 import { bracketMatching } from "./CellInput/block_matcher_plugin.js"
 import { cl } from "../common/ClassTable.js"
-import { HighlightLineFacet, highlightLinePlugin } from "./CellInput/highlight_line.js"
+import { HighlightLineFacet, HighlightRangeFacet, highlightLinePlugin, highlightRangePlugin } from "./CellInput/highlight_line.js"
 import { commentKeymap } from "./CellInput/comment_mixed_parsers.js"
 import { ScopeStateField } from "./CellInput/scopestate_statefield.js"
 import { mod_d_command } from "./CellInput/mod_d_command.js"
@@ -373,8 +374,10 @@ export const CellInput = ({
     set_show_logs,
     set_cell_disabled,
     cm_highlighted_line,
+    cm_highlighted_range,
     metadata,
     global_definition_locations,
+    cm_diagnostics,
 }) => {
     let pluto_actions = useContext(PlutoActionsContext)
     const { disabled: running_disabled, skip_as_script } = metadata
@@ -384,6 +387,7 @@ export const CellInput = ({
         set_error(null)
         throw to_throw
     }
+
     const notebook_id_ref = useRef(notebook_id)
     notebook_id_ref.current = notebook_id
 
@@ -394,6 +398,7 @@ export const CellInput = ({
     let nbpkg_compartment = useCompartment(newcm_ref, NotebookpackagesFacet.of(nbpkg))
     let global_definitions_compartment = useCompartment(newcm_ref, GlobalDefinitionsFacet.of(global_definition_locations))
     let highlighted_line_compartment = useCompartment(newcm_ref, HighlightLineFacet.of(cm_highlighted_line))
+    let highlighted_range_compartment = useCompartment(newcm_ref, HighlightRangeFacet.of(cm_highlighted_range))
     let editable_compartment = useCompartment(newcm_ref, EditorState.readOnly.of(disable_input))
 
     let on_change_compartment = useCompartment(
@@ -589,9 +594,11 @@ export const CellInput = ({
                     // Compartments coming from react state/props
                     nbpkg_compartment,
                     highlighted_line_compartment,
+                    highlighted_range_compartment,
                     global_definitions_compartment,
                     editable_compartment,
                     highlightLinePlugin(),
+                    highlightRangePlugin(),
 
                     // This is waaaay in front of the keys it is supposed to override,
                     // Which is necessary because it needs to run before *any* keymap,
@@ -631,17 +638,25 @@ export const CellInput = ({
                     // Remove selection on blur
                     EditorView.domEventHandlers({
                         blur: (event, view) => {
-                            // collapse the selection into a single point
-                            view.dispatch({
-                                selection: {
-                                    anchor: view.state.selection.main.head,
-                                },
-                                scrollIntoView: false,
-                            })
-                            // and blur the DOM again (because the previous transaction might have re-focused it)
-                            view.contentDOM.blur()
-
-                            set_cm_forced_focus(null)
+                            // it turns out that this condition is true *exactly* if and only if the blur event was triggered by blurring the window
+                            let caused_by_window_blur = document.activeElement === view.contentDOM
+
+                            if (!caused_by_window_blur) {
+                                // then it's caused by focusing something other than this cell in the editor.
+                                // in this case, we want to collapse the selection into a single point, for aesthetic reasons.
+                                setTimeout(() => {
+                                    view.dispatch({
+                                        selection: {
+                                            anchor: view.state.selection.main.head,
+                                        },
+                                        scrollIntoView: false,
+                                    })
+                                    // and blur the DOM again (because the previous transaction might have re-focused it)
+                                    view.contentDOM.blur()
+                                }, 0)
+
+                                set_cm_forced_focus(null)
+                            }
                         },
                     }),
                     pluto_paste_plugin({
@@ -707,6 +722,12 @@ export const CellInput = ({
                     // Wowww this has been enabled for some time now... wonder if there are issues about this yet ;) - DRAL
                     awesome_line_wrapping,
 
+                    // Reset diagnostics on change
+                    EditorView.updateListener.of((update) => {
+                        if (!update.docChanged) return
+                        update.view.dispatch(setDiagnostics(update.state, []))
+                    }),
+
                     on_change_compartment,
 
                     // This is my weird-ass extension that checks the AST and shows you where
@@ -772,6 +793,14 @@ export const CellInput = ({
         }
     }, [])
 
+    useEffect(() => {
+        if (newcm_ref.current == null) return
+        const cm = newcm_ref.current
+        const diagnostics = cm_diagnostics
+
+        cm.dispatch(setDiagnostics(cm.state, diagnostics))
+    }, [cm_diagnostics])
+
     // Effect to apply "remote_code" to the cell when it changes...
     // ideally this won't be necessary as we'll have actual multiplayer,
     // or something to tell the user that the cell is out of sync.
diff --git a/frontend/components/CellInput/highlight_line.js b/frontend/components/CellInput/highlight_line.js
index f66346f878..d5938350d4 100644
--- a/frontend/components/CellInput/highlight_line.js
+++ b/frontend/components/CellInput/highlight_line.js
@@ -4,6 +4,10 @@ const highlighted_line = Decoration.line({
     attributes: { class: "cm-highlighted-line" },
 })
 
+const highlighted_range = Decoration.mark({
+    attributes: { class: "cm-highlighted-range" },
+})
+
 /**
  * @param {EditorView} view
  */
@@ -17,6 +21,22 @@ function create_line_decorations(view) {
     return Decoration.set([highlighted_line.range(line.from, line.from)])
 }
 
+/**
+ * @param {EditorView} view
+ */
+function create_range_decorations(view) {
+    let range = view.state.facet(HighlightRangeFacet)
+    if (range == null) {
+        return Decoration.set([])
+    }
+    let { from, to } = range
+    if (from < 0 || from == to) {
+        return Decoration.set([])
+    }
+
+    return Decoration.set([highlighted_range.range(from, to)])
+}
+
 /**
  * @type Facet<number?, number?>
  */
@@ -25,6 +45,14 @@ export const HighlightLineFacet = Facet.define({
     compare: (a, b) => a === b,
 })
 
+/**
+ * @type Facet<{from: number, to: number}?, {from: number, to: number}?>
+ */
+export const HighlightRangeFacet = Facet.define({
+    combine: (values) => values[0],
+    compare: (a, b) => a === b,
+})
+
 export const highlightLinePlugin = () =>
     ViewPlugin.fromClass(
         class {
@@ -53,3 +81,33 @@ export const highlightLinePlugin = () =>
             decorations: (v) => v.decorations,
         }
     )
+
+
+export const highlightRangePlugin = () =>
+    ViewPlugin.fromClass(
+        class {
+            updateDecos(view) {
+                this.decorations = create_range_decorations(view)
+            }
+
+            /**
+             * @param {EditorView} view
+             */
+            constructor(view) {
+                this.decorations = Decoration.set([])
+                this.updateDecos(view)
+            }
+
+            /**
+             * @param {ViewUpdate} update
+             */
+            update(update) {
+                if (update.docChanged || update.state.facet(HighlightRangeFacet) !== update.startState.facet(HighlightRangeFacet)) {
+                    this.updateDecos(update.view)
+                }
+            }
+        },
+        {
+            decorations: (v) => v.decorations,
+        }
+    )
diff --git a/frontend/components/CellInput/pluto_autocomplete.js b/frontend/components/CellInput/pluto_autocomplete.js
index 2130d6a484..94885157fc 100644
--- a/frontend/components/CellInput/pluto_autocomplete.js
+++ b/frontend/components/CellInput/pluto_autocomplete.js
@@ -131,7 +131,11 @@ let update_docs_from_autocomplete_selection = (on_update_doc_query) => {
         // The nice thing about this is that we can use the resulting state from the transaction,
         // without updating the actual state of the editor.
         let result_transaction = update.state.update({
-            changes: { from: selected_option.source.from, to: selected_option.source.to, insert: text_to_apply },
+            changes: {
+                from: selected_option.source.from,
+                to: Math.min(selected_option.source.to, update.state.doc.length),
+                insert: text_to_apply,
+            },
         })
 
         // So we can use `get_selected_doc_from_state` on our virtual state
diff --git a/frontend/components/CellOutput.js b/frontend/components/CellOutput.js
index 1b7dd13369..e5cd3d9d45 100644
--- a/frontend/components/CellOutput.js
+++ b/frontend/components/CellOutput.js
@@ -2,7 +2,7 @@ import { html, Component, useRef, useLayoutEffect, useContext } from "../imports
 
 import DOMPurify from "../imports/DOMPurify.js"
 
-import { ErrorMessage } from "./ErrorMessage.js"
+import { ErrorMessage, ParseError } from "./ErrorMessage.js"
 import { TreeView, TableView, DivElement } from "./TreeView.js"
 
 import {
@@ -151,6 +151,9 @@ export const OutputBody = ({ mime, body, cell_id, persist_js_state = false, last
         case "application/vnd.pluto.table+object":
             return html`<${TableView} cell_id=${cell_id} body=${body} persist_js_state=${persist_js_state} sanitize_html=${sanitize_html} />`
             break
+        case "application/vnd.pluto.parseerror+object":
+            return html`<div><${ParseError} cell_id=${cell_id} ...${body} /></div>`
+            break
         case "application/vnd.pluto.stacktrace+object":
             return html`<div><${ErrorMessage} cell_id=${cell_id} ...${body} /></div>`
             break
@@ -385,6 +388,21 @@ const execute_scripttags = async ({ root_node, script_nodes, previous_results_ma
                                         delete notebook.metadata[key]
                                     }),
 
+                                ...(cell == null
+                                    ? {}
+                                    : {
+                                          getCellMetadataExperimental: (key, { cell_id = null } = {}) =>
+                                              pluto_actions.get_notebook()?.cell_inputs?.[cell_id ?? cell.id]?.metadata[key],
+                                          setCellMetadataExperimental: (key, value, { cell_id = null } = {}) =>
+                                              pluto_actions.update_notebook((notebook) => {
+                                                  notebook.cell_inputs[cell_id ?? cell.id].metadata[key] = value
+                                              }),
+                                          deleteCellMetadataExperimental: (key, { cell_id = null } = {}) =>
+                                              pluto_actions.update_notebook((notebook) => {
+                                                  delete notebook.cell_inputs[cell_id ?? cell.id].metadata[key]
+                                              }),
+                                      }),
+
                                 ...observablehq_for_cells,
                             },
                             code,
diff --git a/frontend/components/Editor.js b/frontend/components/Editor.js
index 60085c8c64..42d17cb8e9 100644
--- a/frontend/components/Editor.js
+++ b/frontend/components/Editor.js
@@ -4,7 +4,7 @@ import immer, { applyPatches, produceWithPatches } from "../imports/immer.js"
 import _ from "../imports/lodash.js"
 
 import { empty_notebook_state, set_disable_ui_css } from "../editor.js"
-import { create_pluto_connection } from "../common/PlutoConnection.js"
+import { create_pluto_connection, ws_address_from_base } from "../common/PlutoConnection.js"
 import { init_feedback } from "../common/Feedback.js"
 import { serialize_cells, deserialize_cells, detect_deserializer } from "../common/Serialization.js"
 
@@ -18,7 +18,7 @@ import { RecentlyDisabledInfo, UndoDelete } from "./UndoDelete.js"
 import { SlideControls } from "./SlideControls.js"
 import { Scroller } from "./Scroller.js"
 import { ExportBanner } from "./ExportBanner.js"
-import { Popup } from "./Popup.js"
+import { open_pluto_popup, Popup } from "./Popup.js"
 
 import { slice_utf8, length_utf8 } from "../common/UnicodeTools.js"
 import { has_ctrl_or_cmd_pressed, ctrl_or_cmd_name, is_mac_keyboard, in_textarea_or_input } from "../common/KeyboardShortcuts.js"
@@ -343,6 +343,11 @@ export class Editor extends Component {
 
             is_recording: false,
             recording_waiting_to_start: false,
+
+            slider_server: {
+                connecting: false,
+                interactive: false,
+            },
         }
 
         this.setStatePromise = (fn) => new Promise((r) => this.setState(fn, r))
@@ -842,7 +847,30 @@ patch: ${JSON.stringify(
             setTimeout(init_feedback, 2 * 1000) // 2 seconds - load feedback a little later for snappier UI
         }
 
-        const on_connection_status = (val) => this.setState({ connected: val })
+        const on_connection_status = (val, hopeless) => {
+            this.setState({ connected: val })
+            if (hopeless) {
+                // https://github.com/fonsp/Pluto.jl/issues/55
+                // https://github.com/fonsp/Pluto.jl/issues/2398
+                open_pluto_popup({
+                    type: "warn",
+                    source_element: null,
+                    body: html`<p>A new server was started - this notebook session is no longer running.</p>
+                        <p>Would you like to go back to the main menu?</p>
+                        <br />
+                        <a href="./">Go back</a>
+                        <br />
+                        <a
+                            href="#"
+                            onClick=${(e) => {
+                                e.preventDefault()
+                                window.dispatchEvent(new CustomEvent("close pluto popup"))
+                            }}
+                            >Stay here</a
+                        >`,
+                })
+            }
+        }
 
         const on_reconnect = () => {
             console.warn("Reconnected! Checking states")
@@ -858,7 +886,7 @@ patch: ${JSON.stringify(
         /** @type {import('../common/PlutoConnection').PlutoConnection} */
         this.client = /** @type {import('../common/PlutoConnection').PlutoConnection} */ ({})
 
-        this.connect = (ws_address = undefined) =>
+        this.connect = (/** @type {string | undefined} */ ws_address = undefined) =>
             create_pluto_connection({
                 ws_address: ws_address,
                 on_unrequested_update: on_update,
@@ -1164,13 +1192,13 @@ patch: ${JSON.stringify(
             // if (e.defaultPrevented) {
             //     return
             // }
-            if (e.key.toLowerCase() === "q" && has_ctrl_or_cmd_pressed(e)) {
+            if (e.key?.toLowerCase() === "q" && has_ctrl_or_cmd_pressed(e)) {
                 // This one can't be done as cmd+q on mac, because that closes chrome - Dral
                 if (Object.values(this.state.notebook.cell_results).some((c) => c.running || c.queued)) {
                     this.actions.interrupt_remote()
                 }
                 e.preventDefault()
-            } else if (e.key.toLowerCase() === "s" && has_ctrl_or_cmd_pressed(e)) {
+            } else if (e.key?.toLowerCase() === "s" && has_ctrl_or_cmd_pressed(e)) {
                 const some_cells_ran = this.actions.set_and_run_all_changed_remote_cells()
                 if (!some_cells_ran) {
                     // all cells were in sync allready
@@ -1218,8 +1246,8 @@ patch: ${JSON.stringify(
             }
 
             if (this.state.disable_ui && this.state.backend_launch_phase === BackendLaunchPhase.wait_for_user) {
-                // const code = e.key.charCodeAt(0)
-                if (e.key === "Enter" || e.key.length === 1) {
+                // const code = e.key?.charCodeAt(0)
+                if (e.key === "Enter" || e.key?.length === 1) {
                     if (!document.body.classList.contains("wiggle_binder")) {
                         document.body.classList.add("wiggle_binder")
                         setTimeout(() => {
@@ -1308,7 +1336,7 @@ patch: ${JSON.stringify(
                 count_stat(`article-view`)
             }
         } else {
-            this.connect()
+            this.connect(this.props.launch_params.pluto_server_url ? ws_address_from_base(this.props.launch_params.pluto_server_url) : undefined)
         }
     }
 
diff --git a/frontend/components/ErrorMessage.js b/frontend/components/ErrorMessage.js
index 173243ee9b..60e83a1515 100644
--- a/frontend/components/ErrorMessage.js
+++ b/frontend/components/ErrorMessage.js
@@ -1,5 +1,8 @@
 import { PlutoActionsContext } from "../common/PlutoContext.js"
-import { html, useContext, useState } from "../imports/Preact.js"
+import { EditorState, EditorView, julia_andrey, lineNumbers, syntaxHighlighting } from "../imports/CodemirrorPlutoSetup.js"
+import { html, useContext, useEffect, useLayoutEffect, useRef, useState } from "../imports/Preact.js"
+import { pluto_syntax_colors } from "./CellInput.js"
+import { Editor } from "./Editor.js"
 
 const StackFrameFilename = ({ frame, cell_id }) => {
     const sep_index = frame.file.indexOf("#==#")
@@ -38,6 +41,43 @@ const Funccall = ({ frame }) => {
 
 const insert_commas_and_and = (/** @type {any[]} */ xs) => xs.flatMap((x, i) => (i === xs.length - 1 ? [x] : i === xs.length - 2 ? [x, " and "] : [x, ", "]))
 
+export const ParseError = ({ cell_id, diagnostics }) => {
+    useEffect(() => {
+        window.dispatchEvent(
+            new CustomEvent("cell_diagnostics", {
+                detail: {
+                    cell_id,
+                    diagnostics,
+                },
+            })
+        )
+        return () => window.dispatchEvent(new CustomEvent("cell_diagnostics", { detail: { cell_id, diagnostics: [] } }))
+    }, [diagnostics])
+
+    return html`
+        <jlerror>
+            <header><p>Syntax error</p></header>
+            <section>
+              <ol>
+                  ${diagnostics.map(
+                    ({ message, from, to, line }) =>
+                        html`<li onmouseenter=${() => // NOTE: this could be moved move to `StackFrameFilename`
+                                window.dispatchEvent(new CustomEvent("cell_highlight_range", { detail: { cell_id, from, to }}))
+                        }
+                        onmouseleave=${() =>
+                                window.dispatchEvent(new CustomEvent("cell_highlight_range", { detail: { cell_id, from: null, to: null }}))
+                        }
+                      >
+                            ${message}<span>@</span>
+                            <${StackFrameFilename} frame=${{file: "#==#" + cell_id, line}} cell_id=${cell_id} />
+                        </li>`)
+                    }
+              </ol>
+            </section>
+        </jlerror>
+    `;
+}
+
 export const ErrorMessage = ({ msg, stacktrace, cell_id }) => {
     let pluto_actions = useContext(PlutoActionsContext)
     const default_rewriter = {
@@ -62,9 +102,9 @@ export const ErrorMessage = ({ msg, stacktrace, cell_id }) => {
                         <a
                             href="#"
                             onClick=${(e) => {
-                                e.preventDefault()
-                                pluto_actions.split_remote_cell(cell_id, boundaries, true)
-                            }}
+                            e.preventDefault()
+                            pluto_actions.split_remote_cell(cell_id, boundaries, true)
+                        }}
                             >Split this cell into ${boundaries.length} cells</a
                         >, or
                     </p>`
@@ -137,6 +177,11 @@ export const ErrorMessage = ({ msg, stacktrace, cell_id }) => {
                     }
                 }),
         },
+        {
+            pattern: /^syntax: (.*)$/,
+            display: default_rewriter.display,
+            show_stacktrace: () => false,
+        },
         {
             pattern: /^UndefVarError: (.*) not defined\.?$/,
             display: (/** @type{string} */ x) => {
@@ -183,14 +228,14 @@ export const ErrorMessage = ({ msg, stacktrace, cell_id }) => {
             : html`<section>
                   <ol>
                       ${stacktrace.map(
-                          (frame) =>
-                              html`<li>
+                (frame) =>
+                    html`<li>
                                   <${Funccall} frame=${frame} />
                                   <span>@</span>
                                   <${StackFrameFilename} frame=${frame} cell_id=${cell_id} />
                                   ${frame.inlined ? html`<span>[inlined]</span>` : null}
                               </li>`
-                      )}
+            )}
                   </ol>
               </section>`}
     </jlerror>`
diff --git a/frontend/components/ExportBanner.js b/frontend/components/ExportBanner.js
index 0c1bac5383..2188763d9b 100644
--- a/frontend/components/ExportBanner.js
+++ b/frontend/components/ExportBanner.js
@@ -26,8 +26,23 @@ const Square = ({ fill }) => html`
     </svg>
 `
 
-//@ts-ignore
-window.enable_secret_pluto_recording = true
+export const WarnForVisisblePasswords = () => {
+    if (
+        Array.from(document.querySelectorAll("bond")).some((bond_el) =>
+            Array.from(bond_el.querySelectorAll(`input[type="password"]`)).some((input) => {
+                // @ts-ignore
+                if (input?.value !== "") {
+                    input.scrollIntoView()
+                    return true
+                }
+            })
+        )
+    ) {
+        alert(
+            "Warning: this notebook includes a password input with something typed in it. The contents of this password field will be included in the exported file in an unsafe way. \n\nClear the password field and export again to avoid this problem."
+        )
+    }
+}
 
 export const ExportBanner = ({ notebook_id, onClose, notebookfile_url, notebookexport_url, start_recording }) => {
     // @ts-ignore
@@ -49,7 +64,16 @@ export const ExportBanner = ({ notebook_id, onClose, notebookfile_url, notebooke
                     <header><${Triangle} fill="#a270ba" /> Notebook file</header>
                     <section>Download a copy of the <b>.jl</b> script.</section>
                 </a>
-                <a href=${notebookexport_url} target="_blank" class="export_card" download="" onClick=${(e) => exportNotebook(e, 1)}>
+                <a
+                    href=${notebookexport_url}
+                    target="_blank"
+                    class="export_card"
+                    download=""
+                    onClick=${(e) => {
+                        WarnForVisisblePasswords()
+                        exportNotebook(e, 1)
+                    }}
+                >
                     <header><${Square} fill="#E86F51" /> Static HTML</header>
                     <section>An <b>.html</b> file for your web page, or to share online.</section>
                 </a>
@@ -57,26 +81,22 @@ export const ExportBanner = ({ notebook_id, onClose, notebookfile_url, notebooke
                     <header><${Square} fill="#619b3d" /> PDF</header>
                     <section>A static <b>.pdf</b> file for print or email.</section>
                 </a>
-                ${
-                    //@ts-ignore
-                    window.enable_secret_pluto_recording
-                        ? html`
-                              <div class="export_title">record</div>
-                              <a
-                                  href="#"
-                                  onClick=${(e) => {
-                                      start_recording()
-                                      onClose()
-                                      e.preventDefault()
-                                  }}
-                                  class="export_card"
-                              >
-                                  <header><${Circle} fill="#E86F51" /> Record <em>(preview)</em></header>
-                                  <section>Capture the entire notebook, and any changes you make.</section>
-                              </a>
-                          `
-                        : null
-                }
+                ${html`
+                    <div class="export_title">record</div>
+                    <a
+                        href="#"
+                        onClick=${(e) => {
+                            WarnForVisisblePasswords()
+                            start_recording()
+                            onClose()
+                            e.preventDefault()
+                        }}
+                        class="export_card"
+                    >
+                        <header><${Circle} fill="#E86F51" /> Record <em>(preview)</em></header>
+                        <section>Capture the entire notebook, and any changes you make.</section>
+                    </a>
+                `}
                 <div class="export_small_btns">
                     <button
                         title="Edit frontmatter"
diff --git a/frontend/components/FrontmatterInput.js b/frontend/components/FrontmatterInput.js
index 3ca04e3d24..a60f4b5b6a 100644
--- a/frontend/components/FrontmatterInput.js
+++ b/frontend/components/FrontmatterInput.js
@@ -1,10 +1,12 @@
 import { html, Component, useRef, useLayoutEffect, useState, useEffect } from "../imports/Preact.js"
 import { has_ctrl_or_cmd_pressed } from "../common/KeyboardShortcuts.js"
+import _ from "../imports/lodash.js"
 
 import "https://cdn.jsdelivr.net/gh/fonsp/rebel-tag-input@1.0.6/lib/rebel-tag-input.mjs"
 
 //@ts-ignore
 import dialogPolyfill from "https://cdn.jsdelivr.net/npm/dialog-polyfill@0.5.6/dist/dialog-polyfill.esm.min.js"
+import immer from "../imports/immer.js"
 
 /**
  * @param {{
@@ -23,9 +25,12 @@ export const FrontMatterInput = ({ remote_frontmatter, set_remote_frontmatter })
     //     console.log("New frontmatter:", frontmatter)
     // }, [frontmatter])
 
-    const fm_setter = (key) => (value) => {
-        set_frontmatter((fm) => ({ ...fm, [key]: value }))
-    }
+    const fm_setter = (key) => (value) =>
+        set_frontmatter(
+            immer((fm) => {
+                _.set(fm, key, value)
+            })
+        )
 
     const dialog_ref = useRef(/** @type {HTMLDialogElement?} */ (null))
     useLayoutEffect(() => {
@@ -42,10 +47,26 @@ export const FrontMatterInput = ({ remote_frontmatter, set_remote_frontmatter })
         close()
     }
     const submit = () => {
-        set_remote_frontmatter(frontmatter).then(() => alert("Frontmatter synchronized ✔\n\nThese parameters will be used in future exports."))
+        set_remote_frontmatter(clean_data(frontmatter) ?? {}).then(() =>
+            alert("Frontmatter synchronized ✔\n\nThese parameters will be used in future exports.")
+        )
         close()
     }
 
+    const clean_data = (obj) => {
+        let a = _.isPlainObject(obj)
+            ? Object.fromEntries(
+                  Object.entries(obj)
+                      .map(([key, val]) => [key, clean_data(val)])
+                      .filter(([key, val]) => val != null)
+              )
+            : _.isArray(obj)
+            ? obj.map(clean_data).filter((x) => x != null)
+            : obj
+
+        return _.isEmpty(a) ? null : a
+    }
+
     useLayoutEffect(() => {
         window.addEventListener("open pluto frontmatter", open)
         return () => {
@@ -68,43 +89,91 @@ export const FrontMatterInput = ({ remote_frontmatter, set_remote_frontmatter })
         description: null,
         date: null,
         tags: [],
+        author: [{}],
         ...frontmatter,
     }
 
-    return html`<dialog ref=${dialog_ref} class="pluto-frontmatter">
-        <h1>Frontmatter</h1>
-        <p>
-            If you are publishing this notebook on the web, you can set the parameters below to provide HTML metadata. This is useful for search engines and
-            social media.
-        </p>
-        <div class="fm-table">
-            ${Object.entries(frontmatter_with_defaults).map(([key, value]) => {
-                let id = `fm-${key}`
-                return html`
-                    <label for=${id}>${key}</label>
-                    <${Input} type=${field_type(key)} id=${id} value=${value} on_value=${fm_setter(key)} />
-                    <button
-                        class="deletefield"
-                        title="Delete field"
-                        onClick=${() => {
-                            set_frontmatter((fm) => Object.fromEntries(Object.entries(fm).filter(([k]) => k !== key)))
-                        }}
-                    >
-                        ✕
-                    </button>
-                `
-            })}
+    const show_entry = ([key, value]) => !((_.isArray(value) && field_type(key) !== "tags") || _.isPlainObject(value))
+
+    const entries_input = (data, base_path) => {
+        return html`
+            ${Object.entries(data)
+                .filter(show_entry)
+                .map(([key, value]) => {
+                    let path = `${base_path}${key}`
+                    let id = `fm-${path}`
+                    return html`
+                        <label for=${id}>${key}</label>
+                        <${Input} type=${field_type(key)} id=${id} value=${value} on_value=${fm_setter(path)} />
+                        <button
+                            class="deletefield"
+                            title="Delete field"
+                            onClick=${() => {
+                                //  TODO
+                                set_frontmatter(
+                                    immer((fm) => {
+                                        _.unset(fm, path)
+                                    })
+                                )
+                            }}
+                        >
+                            ✕
+                        </button>
+                    `
+                })}
             <button
                 class="addentry"
                 onClick=${() => {
                     const fieldname = prompt("Field name:")
                     if (fieldname) {
-                        set_frontmatter((fm) => ({ ...fm, [fieldname]: null }))
+                        set_frontmatter(
+                            immer((fm) => {
+                                _.set(fm, `${base_path}${fieldname}`, null)
+                            })
+                        )
                     }
                 }}
             >
                 Add entry +
             </button>
+        `
+    }
+
+    return html`<dialog ref=${dialog_ref} class="pluto-frontmatter">
+        <h1>Frontmatter</h1>
+        <p>
+            If you are publishing this notebook on the web, you can set the parameters below to provide HTML metadata. This is useful for search engines and
+            social media.
+        </p>
+        <div class="fm-table">
+            ${entries_input(frontmatter_with_defaults, ``)}
+            ${!_.isArray(frontmatter_with_defaults.author)
+                ? null
+                : frontmatter_with_defaults.author.map((author, i) => {
+                      let author_with_defaults = {
+                          name: null,
+                          url: null,
+                          ...author,
+                      }
+
+                      return html`
+                          <fieldset class="fm-table">
+                              <legend>Author ${i + 1}</legend>
+
+                              ${entries_input(author_with_defaults, `author[${i}].`)}
+                          </fieldset>
+                      `
+                  })}
+            ${!_.isArray(frontmatter_with_defaults.author)
+                ? null
+                : html`<button
+                      class="addentry"
+                      onClick=${() => {
+                          set_frontmatter((fm) => ({ ...fm, author: [...(fm?.author ?? []), {}] }))
+                      }}
+                  >
+                      Add author +
+                  </button>`}
         </div>
 
         <div class="final"><button onClick=${cancel}>Cancel</button><button onClick=${submit}>Save</button></div>
diff --git a/frontend/components/Popup.js b/frontend/components/Popup.js
index 289554a757..3c871680ff 100644
--- a/frontend/components/Popup.js
+++ b/frontend/components/Popup.js
@@ -26,7 +26,7 @@ export const help_circle_icon = new URL("https://cdn.jsdelivr.net/gh/ionic-team/
 
 /**
  * @typedef MiscPopupDetails
- * @property {string} type
+ * @property {"info" | "warn"} type
  * @property {import("../imports/Preact.js").ReactElement} body
  * @property {HTMLElement?} source_element
  */
@@ -48,10 +48,15 @@ export const Popup = ({ notebook, disable_input }) => {
         const el = e.detail.source_element
         recent_source_element_ref.current = el
 
-        const elb = el.getBoundingClientRect()
-        const bodyb = document.body.getBoundingClientRect()
+        if (el == null) {
+            pos_ref.current = `top: 20%; left: 50%; transform: translate(-50%, -50%); position: fixed;`
+        } else {
+            const elb = el.getBoundingClientRect()
+            const bodyb = document.body.getBoundingClientRect()
+
+            pos_ref.current = `top: ${0.5 * (elb.top + elb.bottom) - bodyb.top}px; left: min(max(0px,100vw - 251px - 30px), ${elb.right - bodyb.left}px);`
+        }
 
-        pos_ref.current = `top: ${0.5 * (elb.top + elb.bottom) - bodyb.top}px; left: min(max(0px,100vw - 251px - 30px), ${elb.right - bodyb.left}px);`
         set_recent_event(e.detail)
     }
 
@@ -90,6 +95,7 @@ export const Popup = ({ notebook, disable_input }) => {
     return html`<pluto-popup
         class=${cl({
             visible: recent_event != null,
+            [type ?? ""]: type != null,
         })}
         style="${pos_ref.current}"
     >
@@ -100,7 +106,7 @@ export const Popup = ({ notebook, disable_input }) => {
                   recent_event=${recent_event}
                   clear_recent_event=${() => set_recent_event(null)}
               />`
-            : type === "info"
+            : type === "info" || type === "warn"
             ? html`<div>${recent_event?.body}</div>`
             : null}
     </pluto-popup>`
diff --git a/frontend/components/RunArea.js b/frontend/components/RunArea.js
index 6cdb33d1a6..db4b3a5fc3 100644
--- a/frontend/components/RunArea.js
+++ b/frontend/components/RunArea.js
@@ -33,10 +33,10 @@ export const RunArea = ({
     }
 
     const titlemap = {
-        interrupt: "Interrupt",
+        interrupt: "Interrupt (Ctrl + Q)",
         save: "Save code without running",
         jump: "This cell depends on a disabled cell",
-        run: "Run cell",
+        run: "Run cell (Shift + Enter)",
     }
 
     const on_double_click = (/** @type {MouseEvent} */ e) => {
diff --git a/frontend/components/SelectionArea.js b/frontend/components/SelectionArea.js
index 7f145bb7dd..eb705ad324 100644
--- a/frontend/components/SelectionArea.js
+++ b/frontend/components/SelectionArea.js
@@ -151,7 +151,7 @@ export const SelectionArea = ({ on_selection, set_scroller, cell_order }) => {
 
         // Ctrl+A to select all cells
         const onkeydown = (e) => {
-            if (e.key.toLowerCase() === "a" && has_ctrl_or_cmd_pressed(e)) {
+            if (e.key?.toLowerCase() === "a" && has_ctrl_or_cmd_pressed(e)) {
                 // if you are not writing text somewhere else
                 if (document.activeElement === document.body && (window.getSelection()?.isCollapsed ?? true)) {
                     on_selection(cell_order)
diff --git a/frontend/components/SlideControls.js b/frontend/components/SlideControls.js
index 60a6380eb0..0b096d6996 100644
--- a/frontend/components/SlideControls.js
+++ b/frontend/components/SlideControls.js
@@ -1,6 +1,35 @@
-import { html } from "../imports/Preact.js"
+import { html, useRef, useState, useLayoutEffect, useEffect } from "../imports/Preact.js"
+import { open_pluto_popup } from "./Popup.js"
 
 export const SlideControls = () => {
+    const button_prev_ref = useRef(/** @type {HTMLButtonElement?} */ (null))
+    const button_next_ref = useRef(/** @type {HTMLButtonElement?} */ (null))
+
+    const [presenting, set_presenting] = useState(false)
+
+    const move_slides_with_keyboard = (/** @type {KeyboardEvent} */ e) => {
+        const activeElement = document.activeElement
+        if (
+            activeElement != null &&
+            activeElement !== document.body &&
+            activeElement !== button_prev_ref.current &&
+            activeElement !== button_next_ref.current
+        ) {
+            // We do not move slides with arrow if we have an active element
+            return
+        }
+        if (e.key === "ArrowLeft" || e.key === "PageUp") {
+            button_prev_ref.current?.click()
+        } else if (e.key === "ArrowRight" || e.key === " " || e.key === "PageDown") {
+            button_next_ref.current?.click()
+        } else if (e.key === "Escape") {
+            set_presenting(false)
+        } else {
+            return
+        }
+        e.preventDefault()
+    }
+
     const calculate_slide_positions = (/** @type {Event} */ e) => {
         const notebook_node = /** @type {HTMLElement?} */ (e.target)?.closest("pluto-editor")?.querySelector("pluto-notebook")
         if (!notebook_node) return []
@@ -40,15 +69,29 @@ export const SlideControls = () => {
         if (pos) window.scrollTo(window.pageXOffset, pos)
     }
 
+    const presenting_ref = useRef(false)
+    presenting_ref.current = presenting
     // @ts-ignore
     window.present = () => {
-        document.body.classList.toggle("presentation")
+        set_presenting(!presenting_ref.current)
     }
 
+    useLayoutEffect(() => {
+        document.body.classList.toggle("presentation", presenting)
+
+        if (!presenting) return // We do not add listeners if not presenting
+
+        window.addEventListener("keydown", move_slides_with_keyboard)
+
+        return () => {
+            window.removeEventListener("keydown", move_slides_with_keyboard)
+        }
+    }, [presenting])
+
     return html`
         <nav id="slide_controls">
-            <button class="changeslide prev" title="Previous slide" onClick=${go_previous_slide}><span></span></button>
-            <button class="changeslide next" title="Next slide" onClick=${go_next_slide}><span></span></button>
+            <button ref=${button_prev_ref} class="changeslide prev" title="Previous slide" onClick=${go_previous_slide}><span></span></button>
+            <button ref=${button_next_ref} class="changeslide next" title="Next slide" onClick=${go_next_slide}><span></span></button>
         </nav>
     `
 }
diff --git a/frontend/components/welcome/Welcome.js b/frontend/components/welcome/Welcome.js
index f52fc7aeb3..aca858f838 100644
--- a/frontend/components/welcome/Welcome.js
+++ b/frontend/components/welcome/Welcome.js
@@ -2,7 +2,7 @@ import _ from "../../imports/lodash.js"
 import { html, useEffect, useState, useRef } from "../../imports/Preact.js"
 import * as preact from "../../imports/Preact.js"
 
-import { create_pluto_connection } from "../../common/PlutoConnection.js"
+import { create_pluto_connection, ws_address_from_base } from "../../common/PlutoConnection.js"
 import { new_update_message } from "../../common/NewUpdateMessage.js"
 import { Open } from "./Open.js"
 import { Recent } from "./Recent.js"
@@ -26,6 +26,7 @@ import default_featured_sources from "../../featured_sources.js"
 /**
  * @typedef LaunchParameters
  * @type {{
+ * pluto_server_url: string?,
  * featured_direct_html_links: boolean,
  * featured_sources: import("./Featured.js").FeaturedSource[]?,
  * featured_source_url?: string,
@@ -67,6 +68,7 @@ export const Welcome = ({ launch_params }) => {
             on_unrequested_update: on_update,
             on_connection_status: on_connection_status,
             on_reconnect: () => true,
+            ws_address: launch_params.pluto_server_url ? ws_address_from_base(launch_params.pluto_server_url) : undefined,
         })
         client_promise.then(async (client) => {
             Object.assign(client_ref.current, client)
diff --git a/frontend/editor.css b/frontend/editor.css
index f05f0dc8d0..7816a9c5e6 100644
--- a/frontend/editor.css
+++ b/frontend/editor.css
@@ -452,6 +452,11 @@ pluto-output mjx-assistive-mml {
     height: 1px;
 }
 
+/* Avoid scrollbar in cells that contain just a h3 element, like the h3 headers in https://computationalthinking.mit.edu/Fall22/images_abstractions/transformations_and_autodiff/ */
+.raw-html-wrapper > div.markdown {
+    overflow: hidden;
+}
+
 /* HEADER */
 
 header#pluto-nav {
@@ -497,7 +502,7 @@ aside#export div#container {
     flex-direction: row;
     display: flex;
     max-width: 1000px;
-    padding-right: 20px;
+    padding-right: 10em;
     margin: 0 auto;
 }
 header aside#export div#container {
@@ -548,10 +553,14 @@ a.export_card section {
     padding: 3px;
 }
 aside#export .export_small_btns {
-    margin-left: auto;
-    height: 60px;
     display: flex;
     flex-direction: row;
+    padding: 0.9em;
+    border-radius: 0.9em;
+    position: absolute;
+    right: 0.8em;
+    top: 0em;
+    background: var(--export-bg-color);
 }
 body.static_preview button.toggle_export {
     display: none;
@@ -1231,6 +1240,7 @@ pluto-input .cm-editor .cm-line {
     transition: background-color 0.15s ease-in-out;
 }
 
+pluto-input .cm-editor span.cm-highlighted-range,
 pluto-input .cm-editor .cm-line.cm-highlighted-line {
     background-color: #bdbdbd68;
     border-radius: 3px;
@@ -1518,7 +1528,7 @@ pluto-input > button > span {
     }
 }
 
-@media screen and (any-pointer: coarse) {
+@media screen and (pointer: coarse) {
     pluto-cell > button,
     pluto-cell > pluto-runarea {
         opacity: 0;
@@ -1809,6 +1819,11 @@ pluto-popup > * {
     position: absolute;
 }
 
+pluto-popup.warn > * {
+    background: var(--pluto-logs-warn-color);
+    border-color: var(--pluto-logs-warn-accent-color);
+}
+
 pluto-popup code.auto_disabled_variable {
     font-family: var(--julia-mono-font-stack);
     font-size: 0.8rem;
@@ -1928,6 +1943,9 @@ pluto-runarea {
     border-bottom-left-radius: 5px;
     border-bottom-right-radius: 5px;
     border-top: none;
+    /* One less than z-index for pluto-input .cm-editor.
+       Otherwise it gets on top of the tooltips */
+    z-index: 19;
 }
 
 pluto-runarea > span {
@@ -2326,6 +2344,7 @@ pluto-helpbox.hidden > section {
 }
 .helpbox-docs > section h1 {
     font-size: 1.3rem;
+    overflow-wrap: anywhere;
 }
 .helpbox-docs > section pre {
     padding: 0.7rem 0.5rem;
@@ -2654,7 +2673,7 @@ footer button {
     font-size: 0.75rem;
 }
 
-#info {
+footer #info {
     max-width: 9400px;
     margin: 0 auto;
     padding: 1rem;
@@ -3041,6 +3060,12 @@ button.floating_back_button {
     border-radius: 4px;
 }
 
+.cm-tooltip-lint {
+    font-family: "JuliaMono";
+    font-size: 0.75rem;
+    z-index: 100;
+}
+
 .cm-tooltip-autocomplete {
     max-height: calc(20 * 16px);
     box-sizing: content-box;
@@ -3178,10 +3203,10 @@ pluto-input .cm-editor .cm-content {
     padding: 2px 0px;
 }
 
-.cm-editor .cm-selectionBackground {
+.cm-editor .cm-scroller > .cm-selectionLayer .cm-selectionBackground {
     background: var(--cm-selection-background-blurred);
 }
-.cm-editor.cm-focused .cm-selectionBackground {
+.cm-editor.cm-focused .cm-scroller > .cm-selectionLayer .cm-selectionBackground {
     background: var(--cm-selection-background);
 }
 
@@ -3408,7 +3433,6 @@ pluto-cell.hooked_up pluto-output {
 }
 
 .pluto-frontmatter label {
-    text-transform: capitalize;
     font-weight: 500;
 }
 
@@ -3425,6 +3449,10 @@ pluto-cell.hooked_up pluto-output {
     margin-top: 0.5em;
 }
 
+.pluto-frontmatter fieldset {
+    grid-column: 1/4;
+}
+
 .pluto-frontmatter .final {
     display: flex;
     margin-top: 2rem;
diff --git a/frontend/imports/CodemirrorPlutoSetup.d.ts b/frontend/imports/CodemirrorPlutoSetup.d.ts
index 6919393ed4..4e298e6d9d 100644
--- a/frontend/imports/CodemirrorPlutoSetup.d.ts
+++ b/frontend/imports/CodemirrorPlutoSetup.d.ts
@@ -1865,6 +1865,17 @@ declare type Attrs = {
     [name: string]: string;
 };
 
+/**
+Basic rectangle type.
+*/
+interface Rect {
+    readonly left: number;
+    readonly right: number;
+    readonly top: number;
+    readonly bottom: number;
+}
+declare type ScrollStrategy = "nearest" | "start" | "end" | "center";
+
 interface MarkDecorationSpec {
     /**
     Whether the mark covers its start and end position or not. This
@@ -2013,7 +2024,7 @@ declare abstract class WidgetType {
     couldn't (in which case the widget will be redrawn). The default
     implementation just returns false.
     */
-    updateDOM(dom: HTMLElement): boolean;
+    updateDOM(dom: HTMLElement, view: EditorView): boolean;
     /**
     The estimated height this widget will have, to be used when
     estimating the height of content that hasn't been drawn. May
@@ -2028,6 +2039,14 @@ declare abstract class WidgetType {
     */
     ignoreEvent(event: Event): boolean;
     /**
+    Override the way screen coordinates for positions at/in the
+    widget are found. `pos` will be the offset into the widget, and
+    `side` the side of the position that is being queried—less than
+    zero for before, greater than zero for after, and zero for
+    directly at that position.
+    */
+    coordsAt(dom: HTMLElement, pos: number, side: number): Rect | null;
+    /**
     This is called when the an instance of the widget is removed
     from the editor view.
     */
@@ -2130,17 +2149,6 @@ declare abstract class Decoration extends RangeValue {
     static none: DecorationSet;
 }
 
-/**
-Basic rectangle type.
-*/
-interface Rect {
-    readonly left: number;
-    readonly right: number;
-    readonly top: number;
-    readonly bottom: number;
-}
-declare type ScrollStrategy = "nearest" | "start" | "end" | "center";
-
 /**
 Command functions are used in key bindings and other types of user
 actions. Given an editor view, they check whether their effect can
@@ -2841,6 +2849,11 @@ declare class EditorView {
     */
     static inputHandler: Facet<(view: EditorView, from: number, to: number, text: string) => boolean, readonly ((view: EditorView, from: number, to: number, text: string) => boolean)[]>;
     /**
+    This facet can be used to provide functions that create effects
+    to be dispatched when the editor's focus state changes.
+    */
+    static focusChangeEffect: Facet<(state: EditorState, focusing: boolean) => StateEffect<any> | null, readonly ((state: EditorState, focusing: boolean) => StateEffect<any> | null)[]>;
+    /**
     By default, the editor assumes all its content has the same
     [text direction](https://codemirror.net/6/docs/ref/#view.Direction). Configure this with a `true`
     value to make it read the text direction of every (rendered)
@@ -3216,99 +3229,458 @@ Create a line number gutter extension.
 */
 declare function lineNumbers(config?: LineNumberConfig): Extension;
 
+/**
+Highlighting tags are markers that denote a highlighting category.
+They are [associated](#highlight.styleTags) with parts of a syntax
+tree by a language mode, and then mapped to an actual CSS style by
+a [highlighter](#highlight.Highlighter).
+
+Because syntax tree node types and highlight styles have to be
+able to talk the same language, CodeMirror uses a mostly _closed_
+[vocabulary](#highlight.tags) of syntax tags (as opposed to
+traditional open string-based systems, which make it hard for
+highlighting themes to cover all the tokens produced by the
+various languages).
+
+It _is_ possible to [define](#highlight.Tag^define) your own
+highlighting tags for system-internal use (where you control both
+the language package and the highlighter), but such tags will not
+be picked up by regular highlighters (though you can derive them
+from standard tags to allow highlighters to fall back to those).
+*/
 declare class Tag {
+    /**
+    The set of this tag and all its parent tags, starting with
+    this one itself and sorted in order of decreasing specificity.
+    */
     readonly set: Tag[];
+    /**
+    Define a new tag. If `parent` is given, the tag is treated as a
+    sub-tag of that parent, and
+    [highlighters](#highlight.tagHighlighter) that don't mention
+    this tag will try to fall back to the parent tag (or grandparent
+    tag, etc).
+    */
     static define(parent?: Tag): Tag;
+    /**
+    Define a tag _modifier_, which is a function that, given a tag,
+    will return a tag that is a subtag of the original. Applying the
+    same modifier to a twice tag will return the same value (`m1(t1)
+    == m1(t1)`) and applying multiple modifiers will, regardless or
+    order, produce the same tag (`m1(m2(t1)) == m2(m1(t1))`).
+    
+    When multiple modifiers are applied to a given base tag, each
+    smaller set of modifiers is registered as a parent, so that for
+    example `m1(m2(m3(t1)))` is a subtype of `m1(m2(t1))`,
+    `m1(m3(t1)`, and so on.
+    */
     static defineModifier(): (tag: Tag) => Tag;
 }
+/**
+A highlighter defines a mapping from highlighting tags and
+language scopes to CSS class names. They are usually defined via
+[`tagHighlighter`](#highlight.tagHighlighter) or some wrapper
+around that, but it is also possible to implement them from
+scratch.
+*/
 interface Highlighter {
+    /**
+    Get the set of classes that should be applied to the given set
+    of highlighting tags, or null if this highlighter doesn't assign
+    a style to the tags.
+    */
     style(tags: readonly Tag[]): string | null;
+    /**
+    When given, the highlighter will only be applied to trees on
+    whose [top](#common.NodeType.isTop) node this predicate returns
+    true.
+    */
     scope?(node: NodeType): boolean;
 }
+/**
+The default set of highlighting [tags](#highlight.Tag).
+
+This collection is heavily biased towards programming languages,
+and necessarily incomplete. A full ontology of syntactic
+constructs would fill a stack of books, and be impractical to
+write themes for. So try to make do with this set. If all else
+fails, [open an
+issue](https://github.com/codemirror/codemirror.next) to propose a
+new tag, or [define](#highlight.Tag^define) a local custom tag for
+your use case.
+
+Note that it is not obligatory to always attach the most specific
+tag possible to an element—if your grammar can't easily
+distinguish a certain type of element (such as a local variable),
+it is okay to style it as its more general variant (a variable).
+
+For tags that extend some parent tag, the documentation links to
+the parent.
+*/
 declare const tags: {
+    /**
+    A comment.
+    */
     comment: Tag;
+    /**
+    A line [comment](#highlight.tags.comment).
+    */
     lineComment: Tag;
+    /**
+    A block [comment](#highlight.tags.comment).
+    */
     blockComment: Tag;
+    /**
+    A documentation [comment](#highlight.tags.comment).
+    */
     docComment: Tag;
+    /**
+    Any kind of identifier.
+    */
     name: Tag;
+    /**
+    The [name](#highlight.tags.name) of a variable.
+    */
     variableName: Tag;
+    /**
+    A type [name](#highlight.tags.name).
+    */
     typeName: Tag;
+    /**
+    A tag name (subtag of [`typeName`](#highlight.tags.typeName)).
+    */
     tagName: Tag;
+    /**
+    A property or field [name](#highlight.tags.name).
+    */
     propertyName: Tag;
+    /**
+    An attribute name (subtag of [`propertyName`](#highlight.tags.propertyName)).
+    */
     attributeName: Tag;
+    /**
+    The [name](#highlight.tags.name) of a class.
+    */
     className: Tag;
+    /**
+    A label [name](#highlight.tags.name).
+    */
     labelName: Tag;
+    /**
+    A namespace [name](#highlight.tags.name).
+    */
     namespace: Tag;
+    /**
+    The [name](#highlight.tags.name) of a macro.
+    */
     macroName: Tag;
+    /**
+    A literal value.
+    */
     literal: Tag;
+    /**
+    A string [literal](#highlight.tags.literal).
+    */
     string: Tag;
+    /**
+    A documentation [string](#highlight.tags.string).
+    */
     docString: Tag;
+    /**
+    A character literal (subtag of [string](#highlight.tags.string)).
+    */
     character: Tag;
+    /**
+    An attribute value (subtag of [string](#highlight.tags.string)).
+    */
     attributeValue: Tag;
+    /**
+    A number [literal](#highlight.tags.literal).
+    */
     number: Tag;
+    /**
+    An integer [number](#highlight.tags.number) literal.
+    */
     integer: Tag;
+    /**
+    A floating-point [number](#highlight.tags.number) literal.
+    */
     float: Tag;
+    /**
+    A boolean [literal](#highlight.tags.literal).
+    */
     bool: Tag;
+    /**
+    Regular expression [literal](#highlight.tags.literal).
+    */
     regexp: Tag;
+    /**
+    An escape [literal](#highlight.tags.literal), for example a
+    backslash escape in a string.
+    */
     escape: Tag;
+    /**
+    A color [literal](#highlight.tags.literal).
+    */
     color: Tag;
+    /**
+    A URL [literal](#highlight.tags.literal).
+    */
     url: Tag;
+    /**
+    A language keyword.
+    */
     keyword: Tag;
+    /**
+    The [keyword](#highlight.tags.keyword) for the self or this
+    object.
+    */
     self: Tag;
+    /**
+    The [keyword](#highlight.tags.keyword) for null.
+    */
     null: Tag;
+    /**
+    A [keyword](#highlight.tags.keyword) denoting some atomic value.
+    */
     atom: Tag;
+    /**
+    A [keyword](#highlight.tags.keyword) that represents a unit.
+    */
     unit: Tag;
+    /**
+    A modifier [keyword](#highlight.tags.keyword).
+    */
     modifier: Tag;
+    /**
+    A [keyword](#highlight.tags.keyword) that acts as an operator.
+    */
     operatorKeyword: Tag;
+    /**
+    A control-flow related [keyword](#highlight.tags.keyword).
+    */
     controlKeyword: Tag;
+    /**
+    A [keyword](#highlight.tags.keyword) that defines something.
+    */
     definitionKeyword: Tag;
+    /**
+    A [keyword](#highlight.tags.keyword) related to defining or
+    interfacing with modules.
+    */
     moduleKeyword: Tag;
+    /**
+    An operator.
+    */
     operator: Tag;
+    /**
+    An [operator](#highlight.tags.operator) that dereferences something.
+    */
     derefOperator: Tag;
+    /**
+    Arithmetic-related [operator](#highlight.tags.operator).
+    */
     arithmeticOperator: Tag;
+    /**
+    Logical [operator](#highlight.tags.operator).
+    */
     logicOperator: Tag;
+    /**
+    Bit [operator](#highlight.tags.operator).
+    */
     bitwiseOperator: Tag;
+    /**
+    Comparison [operator](#highlight.tags.operator).
+    */
     compareOperator: Tag;
+    /**
+    [Operator](#highlight.tags.operator) that updates its operand.
+    */
     updateOperator: Tag;
+    /**
+    [Operator](#highlight.tags.operator) that defines something.
+    */
     definitionOperator: Tag;
+    /**
+    Type-related [operator](#highlight.tags.operator).
+    */
     typeOperator: Tag;
+    /**
+    Control-flow [operator](#highlight.tags.operator).
+    */
     controlOperator: Tag;
+    /**
+    Program or markup punctuation.
+    */
     punctuation: Tag;
+    /**
+    [Punctuation](#highlight.tags.punctuation) that separates
+    things.
+    */
     separator: Tag;
+    /**
+    Bracket-style [punctuation](#highlight.tags.punctuation).
+    */
     bracket: Tag;
+    /**
+    Angle [brackets](#highlight.tags.bracket) (usually `<` and `>`
+    tokens).
+    */
     angleBracket: Tag;
+    /**
+    Square [brackets](#highlight.tags.bracket) (usually `[` and `]`
+    tokens).
+    */
     squareBracket: Tag;
+    /**
+    Parentheses (usually `(` and `)` tokens). Subtag of
+    [bracket](#highlight.tags.bracket).
+    */
     paren: Tag;
+    /**
+    Braces (usually `{` and `}` tokens). Subtag of
+    [bracket](#highlight.tags.bracket).
+    */
     brace: Tag;
+    /**
+    Content, for example plain text in XML or markup documents.
+    */
     content: Tag;
+    /**
+    [Content](#highlight.tags.content) that represents a heading.
+    */
     heading: Tag;
+    /**
+    A level 1 [heading](#highlight.tags.heading).
+    */
     heading1: Tag;
+    /**
+    A level 2 [heading](#highlight.tags.heading).
+    */
     heading2: Tag;
+    /**
+    A level 3 [heading](#highlight.tags.heading).
+    */
     heading3: Tag;
+    /**
+    A level 4 [heading](#highlight.tags.heading).
+    */
     heading4: Tag;
+    /**
+    A level 5 [heading](#highlight.tags.heading).
+    */
     heading5: Tag;
+    /**
+    A level 6 [heading](#highlight.tags.heading).
+    */
     heading6: Tag;
+    /**
+    A prose separator (such as a horizontal rule).
+    */
     contentSeparator: Tag;
+    /**
+    [Content](#highlight.tags.content) that represents a list.
+    */
     list: Tag;
+    /**
+    [Content](#highlight.tags.content) that represents a quote.
+    */
     quote: Tag;
+    /**
+    [Content](#highlight.tags.content) that is emphasized.
+    */
     emphasis: Tag;
+    /**
+    [Content](#highlight.tags.content) that is styled strong.
+    */
     strong: Tag;
+    /**
+    [Content](#highlight.tags.content) that is part of a link.
+    */
     link: Tag;
+    /**
+    [Content](#highlight.tags.content) that is styled as code or
+    monospace.
+    */
     monospace: Tag;
+    /**
+    [Content](#highlight.tags.content) that has a strike-through
+    style.
+    */
     strikethrough: Tag;
+    /**
+    Inserted text in a change-tracking format.
+    */
     inserted: Tag;
+    /**
+    Deleted text.
+    */
     deleted: Tag;
+    /**
+    Changed text.
+    */
     changed: Tag;
+    /**
+    An invalid or unsyntactic element.
+    */
     invalid: Tag;
+    /**
+    Metadata or meta-instruction.
+    */
     meta: Tag;
+    /**
+    [Metadata](#highlight.tags.meta) that applies to the entire
+    document.
+    */
     documentMeta: Tag;
+    /**
+    [Metadata](#highlight.tags.meta) that annotates or adds
+    attributes to a given syntactic element.
+    */
     annotation: Tag;
+    /**
+    Processing instruction or preprocessor directive. Subtag of
+    [meta](#highlight.tags.meta).
+    */
     processingInstruction: Tag;
+    /**
+    [Modifier](#highlight.Tag^defineModifier) that indicates that a
+    given element is being defined. Expected to be used with the
+    various [name](#highlight.tags.name) tags.
+    */
     definition: (tag: Tag) => Tag;
+    /**
+    [Modifier](#highlight.Tag^defineModifier) that indicates that
+    something is constant. Mostly expected to be used with
+    [variable names](#highlight.tags.variableName).
+    */
     constant: (tag: Tag) => Tag;
+    /**
+    [Modifier](#highlight.Tag^defineModifier) used to indicate that
+    a [variable](#highlight.tags.variableName) or [property
+    name](#highlight.tags.propertyName) is being called or defined
+    as a function.
+    */
     function: (tag: Tag) => Tag;
+    /**
+    [Modifier](#highlight.Tag^defineModifier) that can be applied to
+    [names](#highlight.tags.name) to indicate that they belong to
+    the language's standard environment.
+    */
     standard: (tag: Tag) => Tag;
+    /**
+    [Modifier](#highlight.Tag^defineModifier) that indicates a given
+    [names](#highlight.tags.name) is local to some scope.
+    */
     local: (tag: Tag) => Tag;
+    /**
+    A generic variant [modifier](#highlight.Tag^defineModifier) that
+    can be used to tag language-specific alternative variants of
+    some common tag. It is recommended for themes to define special
+    forms of at least the [string](#highlight.tags.string) and
+    [variable name](#highlight.tags.variableName) tags, since those
+    come up a lot.
+    */
     special: (tag: Tag) => Tag;
 };
 
@@ -3561,9 +3933,9 @@ declare class LanguageDescription {
     static matchLanguageName(descs: readonly LanguageDescription[], name: string, fuzzy?: boolean): LanguageDescription | null;
 }
 /**
-Facet for overriding the unit by which indentation happens.
-Should be a string consisting either entirely of spaces or
-entirely of tabs. When not set, this defaults to 2 spaces.
+Facet for overriding the unit by which indentation happens. Should
+be a string consisting either entirely of the same whitespace
+character. When not set, this defaults to 2 spaces.
 */
 declare const indentUnit: Facet<string, string>;
 /**
@@ -3844,7 +4216,7 @@ The default keymap. Includes all bindings from
 - Shift-Alt-ArrowUp: [`copyLineUp`](https://codemirror.net/6/docs/ref/#commands.copyLineUp)
 - Shift-Alt-ArrowDown: [`copyLineDown`](https://codemirror.net/6/docs/ref/#commands.copyLineDown)
 - Escape: [`simplifySelection`](https://codemirror.net/6/docs/ref/#commands.simplifySelection)
-- Ctrl-Enter (Comd-Enter on macOS): [`insertBlankLine`](https://codemirror.net/6/docs/ref/#commands.insertBlankLine)
+- Ctrl-Enter (Cmd-Enter on macOS): [`insertBlankLine`](https://codemirror.net/6/docs/ref/#commands.insertBlankLine)
 - Alt-l (Ctrl-l on macOS): [`selectLine`](https://codemirror.net/6/docs/ref/#commands.selectLine)
 - Ctrl-i (Cmd-i on macOS): [`selectParentSyntax`](https://codemirror.net/6/docs/ref/#commands.selectParentSyntax)
 - Ctrl-[ (Cmd-[ on macOS): [`indentLess`](https://codemirror.net/6/docs/ref/#commands.indentLess)
@@ -3933,6 +4305,19 @@ interface CompletionConfig {
         position: number;
     }[];
     /**
+    By default, [info](https://codemirror.net/6/docs/ref/#autocomplet.Completion.info) tooltips are
+    placed to the side of the selected. This option can be used to
+    override that. It will be given rectangles for the list of
+    completions, the selected option, the info element, and the
+    availble [tooltip space](https://codemirror.net/6/docs/ref/#view.tooltips^config.tooltipSpace),
+    and should return style and/or class strings for the info
+    element.
+    */
+    positionInfo?: (view: EditorView, list: Rect, option: Rect, info: Rect, space: Rect) => {
+        style?: string;
+        class?: string;
+    };
+    /**
     The comparison function to use when sorting completions with the same
     match score. Defaults to using
     [`localeCompare`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/localeCompare).
@@ -3997,6 +4382,39 @@ interface Completion {
     down the list, a positive number moves it up.
     */
     boost?: number;
+    /**
+    Can be used to divide the completion list into sections.
+    Completions in a given section (matched by name) will be grouped
+    together, with a heading above them. Options without section
+    will appear above all sections. A string value is equivalent to
+    a `{name}` object.
+    */
+    section?: string | CompletionSection;
+}
+/**
+Object used to describe a completion
+[section](https://codemirror.net/6/docs/ref/#autocomplete.Completion.section). It is recommended to
+create a shared object used by all the completions in a given
+section.
+*/
+interface CompletionSection {
+    /**
+    The name of the section. If no `render` method is present, this
+    will be displayed above the options.
+    */
+    name: string;
+    /**
+    An optional function that renders the section header. Since the
+    headers are shown inside a list, you should make sure the
+    resulting element has a `display: list-item` style.
+    */
+    header?: (section: CompletionSection) => HTMLElement;
+    /**
+    By default, sections are ordered alphabetically by name. To
+    specify an explicit order, `rank` can be used. Sections with a
+    lower rank will be shown above sections with a higher rank.
+    */
+    rank?: number;
 }
 /**
 An instance of this is passed to completion source functions.
@@ -4192,7 +4610,7 @@ interpreted as indicating a placeholder.
 declare function snippet(template: string): (editor: {
     state: EditorState;
     dispatch: (tr: Transaction) => void;
-}, _completion: Completion, from: number, to: number) => void;
+}, completion: Completion, from: number, to: number) => void;
 /**
 A command that clears the active snippet, if any.
 */
@@ -4347,6 +4765,7 @@ type index_d_Completion = Completion;
 type index_d_CompletionContext = CompletionContext;
 declare const index_d_CompletionContext: typeof CompletionContext;
 type index_d_CompletionResult = CompletionResult;
+type index_d_CompletionSection = CompletionSection;
 type index_d_CompletionSource = CompletionSource;
 declare const index_d_acceptCompletion: typeof acceptCompletion;
 declare const index_d_autocompletion: typeof autocompletion;
@@ -4381,6 +4800,7 @@ declare namespace index_d {
     index_d_Completion as Completion,
     index_d_CompletionContext as CompletionContext,
     index_d_CompletionResult as CompletionResult,
+    index_d_CompletionSection as CompletionSection,
     index_d_CompletionSource as CompletionSource,
     index_d_acceptCompletion as acceptCompletion,
     index_d_autocompletion as autocompletion,
@@ -4697,6 +5117,101 @@ declare function html(config?: {
     nestedAttributes?: NestedAttr[];
 }): LanguageSupport;
 
+/**
+Describes a problem or hint for a piece of code.
+*/
+interface Diagnostic {
+    /**
+    The start position of the relevant text.
+    */
+    from: number;
+    /**
+    The end position. May be equal to `from`, though actually
+    covering text is preferable.
+    */
+    to: number;
+    /**
+    The severity of the problem. This will influence how it is
+    displayed.
+    */
+    severity: "info" | "warning" | "error";
+    /**
+    An optional source string indicating where the diagnostic is
+    coming from. You can put the name of your linter here, if
+    applicable.
+    */
+    source?: string;
+    /**
+    The message associated with this diagnostic.
+    */
+    message: string;
+    /**
+    An optional custom rendering function that displays the message
+    as a DOM node.
+    */
+    renderMessage?: () => Node;
+    /**
+    An optional array of actions that can be taken on this
+    diagnostic.
+    */
+    actions?: readonly Action[];
+}
+/**
+An action associated with a diagnostic.
+*/
+interface Action {
+    /**
+    The label to show to the user. Should be relatively short.
+    */
+    name: string;
+    /**
+    The function to call when the user activates this action. Is
+    given the diagnostic's _current_ position, which may have
+    changed since the creation of the diagnostic, due to editing.
+    */
+    apply: (view: EditorView, from: number, to: number) => void;
+}
+declare type DiagnosticFilter = (diagnostics: readonly Diagnostic[]) => Diagnostic[];
+interface LintConfig {
+    /**
+    Time to wait (in milliseconds) after a change before running
+    the linter. Defaults to 750ms.
+    */
+    delay?: number;
+    /**
+    Optional predicate that can be used to indicate when diagnostics
+    need to be recomputed. Linting is always re-done on document
+    changes.
+    */
+    needsRefresh?: null | ((update: ViewUpdate) => boolean);
+    /**
+    Optional filter to determine which diagnostics produce markers
+    in the content.
+    */
+    markerFilter?: null | DiagnosticFilter;
+    /**
+    Filter applied to a set of diagnostics shown in a tooltip. No
+    tooltip will appear if the empty set is returned.
+    */
+    tooltipFilter?: null | DiagnosticFilter;
+}
+/**
+Returns a transaction spec which updates the current set of
+diagnostics, and enables the lint extension if if wasn't already
+active.
+*/
+declare function setDiagnostics(state: EditorState, diagnostics: readonly Diagnostic[]): TransactionSpec;
+/**
+The type of a function that produces diagnostics.
+*/
+declare type LintSource = (view: EditorView) => readonly Diagnostic[] | Promise<readonly Diagnostic[]>;
+/**
+Given a diagnostic source, this function returns an extension that
+enables linting with that source. It will be called whenever the
+editor is idle (after its content changed).
+*/
+declare function linter(source: LintSource, config?: LintConfig): Extension;
+
 /**
 A language provider based on the [Lezer JavaScript
 parser](https://github.com/lezer-parser/javascript), extended with
@@ -4832,6 +5347,12 @@ interface SQLConfig {
     */
     tables?: readonly Completion[];
     /**
+    Similar to `tables`, if you want to provide completion objects
+    for your schemas rather than using the generated ones, pass them
+    here.
+    */
+    schemas?: readonly Completion[];
+    /**
     When given, columns from the named table can be completed
     directly at the top level.
     */
@@ -4893,4 +5414,4 @@ Create an instance of the collaborative editing plugin.
 */
 declare function collab(config?: CollabConfig): Extension;
 
-export { Annotation, Compartment, Decoration, EditorSelection, EditorState, EditorView, Facet, HighlightStyle, NodeProp, PostgreSQL, SelectionRange, StateEffect, StateField, Text, Transaction, TreeCursor, ViewPlugin, ViewUpdate, WidgetType, index_d as autocomplete, bracketMatching, closeBrackets, closeBracketsKeymap, collab, combineConfig, completionKeymap, css, cssLanguage, defaultHighlightStyle, defaultKeymap, drawSelection, foldGutter, foldKeymap, highlightSelectionMatches, highlightSpecialChars, history, historyKeymap, html, htmlLanguage, indentLess, indentMore, indentOnInput, indentUnit, javascript, javascriptLanguage, julia as julia_andrey, keymap, lineNumbers, markdown, markdownLanguage, parseCode, parseMixed, placeholder, python, pythonLanguage, rectangularSelection, searchKeymap, selectNextOccurrence, sql, syntaxHighlighting, syntaxTree, syntaxTreeAvailable, tags };
+export { Annotation, Compartment, Decoration, Diagnostic, EditorSelection, EditorState, EditorView, Facet, HighlightStyle, NodeProp, PostgreSQL, SelectionRange, StateEffect, StateField, Text, Transaction, TreeCursor, ViewPlugin, ViewUpdate, WidgetType, index_d as autocomplete, bracketMatching, closeBrackets, closeBracketsKeymap, collab, combineConfig, completionKeymap, css, cssLanguage, defaultHighlightStyle, defaultKeymap, drawSelection, foldGutter, foldKeymap, highlightSelectionMatches, highlightSpecialChars, history, historyKeymap, html, htmlLanguage, indentLess, indentMore, indentOnInput, indentUnit, javascript, javascriptLanguage, julia as julia_andrey, keymap, lineNumbers, linter, markdown, markdownLanguage, parseCode, parseMixed, placeholder, python, pythonLanguage, rectangularSelection, searchKeymap, selectNextOccurrence, setDiagnostics, sql, syntaxHighlighting, syntaxTree, syntaxTreeAvailable, tags };
diff --git a/frontend/imports/CodemirrorPlutoSetup.js b/frontend/imports/CodemirrorPlutoSetup.js
index ce8c635152..da54f20909 100644
--- a/frontend/imports/CodemirrorPlutoSetup.js
+++ b/frontend/imports/CodemirrorPlutoSetup.js
@@ -59,10 +59,14 @@ import {
     css,
     cssLanguage,
     selectNextOccurrence,
+    linter,
+    setDiagnostics,
     //@ts-ignore
-} from "https://cdn.jsdelivr.net/gh/JuliaPluto/codemirror-pluto-setup@0.28.4/dist/index.es.min.js"
+} from "https://cdn.jsdelivr.net/gh/JuliaPluto/codemirror-pluto-setup@1234.0.0/dist/index.es.min.js"
 
 export {
+    linter,
+    setDiagnostics,
     EditorState,
     EditorSelection,
     Compartment,
diff --git a/frontend/index.js b/frontend/index.js
index 1c918a2115..fc485b3e05 100644
--- a/frontend/index.js
+++ b/frontend/index.js
@@ -22,6 +22,9 @@ const launch_params = {
     featured_source_url: url_params.get("featured_source_url") ?? window.pluto_featured_source_url,
     //@ts-ignore
     featured_source_integrity: url_params.get("featured_source_integrity") ?? window.pluto_featured_source_integrity,
+
+    //@ts-ignore
+    pluto_server_url: url_params.get("pluto_server_url") ?? window.pluto_server_url,
 }
 
 console.log("Launch parameters: ", launch_params)
diff --git a/frontend/light_color.css b/frontend/light_color.css
index 6685329f48..0f7e2ce49f 100644
--- a/frontend/light_color.css
+++ b/frontend/light_color.css
@@ -111,7 +111,7 @@
 
         /*saveall container*/
         --overlay-button-bg: #ffffff;
-        --overlay-button-border: #f3f2f2;
+        --overlay-button-border: hsl(0 4% 91% / 1);
         --overlay-button-border-save: #f3f2f2;
 
         /*input_context_menu*/
diff --git a/frontend/warn_old_browsers.js b/frontend/warn_old_browsers.js
index 2210694be7..cce168f5bf 100644
--- a/frontend/warn_old_browsers.js
+++ b/frontend/warn_old_browsers.js
@@ -3,9 +3,12 @@ function ismodern() {
         // See: https://kangax.github.io/compat-table/es2016plus/
 
         // 2020 check:
-        return eval("let {a, ...r} = {a:1,b:1}; r?.a != r.b; 1 ?? 2")
+        // return eval("let {a, ...r} = {a:1,b:1}; r?.a != r.b; 1 ?? 2")
         // 2021 check:
         // return eval("let {a, ...r} = {a:1,b:1}; r?.a != r.b; 1 ?? 2; a ||= false")
+        // 2021 check (Chrome 85+, Firefox 77+, Safari 13.1+)
+        // Please check with macs
+        return Boolean(String.prototype.replaceAll)
     } catch (ex) {
         return false
     }
diff --git a/src/Configuration.jl b/src/Configuration.jl
index 95236fa6b4..2b7eed6ae9 100644
--- a/src/Configuration.jl
+++ b/src/Configuration.jl
@@ -140,6 +140,7 @@ end
 
 const RUN_NOTEBOOK_ON_LOAD_DEFAULT = true
 const WORKSPACE_USE_DISTRIBUTED_DEFAULT = true
+const WORKSPACE_USE_DISTRIBUTED_STDLIB_DEFAULT = nothing
 const LAZY_WORKSPACE_CREATION_DEFAULT = false
 const CAPTURE_STDOUT_DEFAULT = true
 const WORKSPACE_CUSTOM_STARTUP_EXPR_DEFAULT = nothing
@@ -152,6 +153,7 @@ These options are not intended to be changed during normal use.
 
 - `run_notebook_on_load::Bool = $RUN_NOTEBOOK_ON_LOAD_DEFAULT` Whether to evaluate a notebook on load.
 - `workspace_use_distributed::Bool = $WORKSPACE_USE_DISTRIBUTED_DEFAULT` Whether to start notebooks in a separate process.
+- `workspace_use_distributed_stdlib::Bool? = $WORKSPACE_USE_DISTRIBUTED_STDLIB_DEFAULT` Should we use the Distributed stdlib to run processes? Distributed will be replaced by Malt.jl, you can use this option to already get the old behaviour. `nothing` means: determine automatically (which is currently the same as `true`).
 - `lazy_workspace_creation::Bool = $LAZY_WORKSPACE_CREATION_DEFAULT`
 - `capture_stdout::Bool = $CAPTURE_STDOUT_DEFAULT`
 - `workspace_custom_startup_expr::Union{Nothing,Expr} = $WORKSPACE_CUSTOM_STARTUP_EXPR_DEFAULT` An expression to be evaluated in the workspace process before running notebook code.
@@ -159,6 +161,7 @@ These options are not intended to be changed during normal use.
 @option mutable struct EvaluationOptions
     run_notebook_on_load::Bool = RUN_NOTEBOOK_ON_LOAD_DEFAULT
     workspace_use_distributed::Bool = WORKSPACE_USE_DISTRIBUTED_DEFAULT
+    workspace_use_distributed_stdlib::Union{Bool,Nothing} = WORKSPACE_USE_DISTRIBUTED_STDLIB_DEFAULT
     lazy_workspace_creation::Bool = LAZY_WORKSPACE_CREATION_DEFAULT
     capture_stdout::Bool = CAPTURE_STDOUT_DEFAULT
     workspace_custom_startup_expr::Union{Nothing,Expr} = WORKSPACE_CUSTOM_STARTUP_EXPR_DEFAULT
@@ -292,6 +295,7 @@ function from_flat_kwargs(;
 
         run_notebook_on_load::Bool = RUN_NOTEBOOK_ON_LOAD_DEFAULT,
         workspace_use_distributed::Bool = WORKSPACE_USE_DISTRIBUTED_DEFAULT,
+        workspace_use_distributed_stdlib::Union{Bool,Nothing} = WORKSPACE_USE_DISTRIBUTED_STDLIB_DEFAULT,
         lazy_workspace_creation::Bool = LAZY_WORKSPACE_CREATION_DEFAULT,
         capture_stdout::Bool = CAPTURE_STDOUT_DEFAULT,
         workspace_custom_startup_expr::Union{Nothing,Expr} = WORKSPACE_CUSTOM_STARTUP_EXPR_DEFAULT,
@@ -340,6 +344,7 @@ function from_flat_kwargs(;
     evaluation = EvaluationOptions(;
         run_notebook_on_load,
         workspace_use_distributed,
+        workspace_use_distributed_stdlib,
         lazy_workspace_creation,
         capture_stdout,
         workspace_custom_startup_expr,
diff --git a/src/Pluto.jl b/src/Pluto.jl
index 2cb0eee2ad..8898d058f2 100644
--- a/src/Pluto.jl
+++ b/src/Pluto.jl
@@ -33,6 +33,7 @@ function project_relative_path(root, xs...)
 end
 
 import Pkg
+import Scratch
 
 include_dependency("../Project.toml")
 const PLUTO_VERSION = VersionNumber(Pkg.TOML.parsefile(joinpath(ROOT_DIR, "Project.toml"))["version"])
@@ -99,16 +100,31 @@ export activate_notebook_environment
 
 include("./precompile.jl")
 
-if get(ENV, "JULIA_PLUTO_SHOW_BANNER", "1") != "0" && get(ENV, "CI", "🍄") != "true"
-@info """\n
-    Welcome to Pluto $(PLUTO_VERSION_STR) 🎈
-    Start a notebook server using:
-
-  julia> Pluto.run()
-
-    Have a look at the FAQ:
-    https://github.com/fonsp/Pluto.jl/wiki
-\n"""
+function __init__()
+    # Print a welcome banner
+    if (get(ENV, "JULIA_PLUTO_SHOW_BANNER", "1") != "0" &&
+        get(ENV, "CI", "🍄") != "true" && isinteractive())
+        # Print the banner only once per version, if there isn't
+        # yet a file for this version in banner_shown scratch space.
+        # (Using the Pluto version as the filename enables later
+        # version-specific "what's new" messages.)
+        fn = joinpath(Scratch.@get_scratch!("banner_shown"), PLUTO_VERSION_STR)
+        if !isfile(fn)
+            @info """
+
+              Welcome to Pluto $(PLUTO_VERSION_STR) 🎈
+              Start a notebook server using:
+
+            julia> Pluto.run()
+
+              Have a look at the FAQ:
+              https://github.com/fonsp/Pluto.jl/wiki
+
+            """
+            # create empty file to indicate that we've shown the banner
+            write(fn, "");
+        end
+    end
 end
 
 end
diff --git a/src/analysis/ExpressionExplorer.jl b/src/analysis/ExpressionExplorer.jl
index 50b773d969..67edc5c82a 100644
--- a/src/analysis/ExpressionExplorer.jl
+++ b/src/analysis/ExpressionExplorer.jl
@@ -146,7 +146,7 @@ function get_assignees(ex::Expr)::FunctionName
             # e.g. (x, y) in the ex (x, y) = (1, 23)
             args = ex.args
         end
-        union!(Symbol[], Iterators.map(get_assignees, args)...)
+        mapfoldl(get_assignees, union!, args; init=Symbol[])
         # filter(s->s isa Symbol, ex.args)
     elseif ex.head == :(::)
         # TODO: type is referenced
@@ -156,7 +156,7 @@ function get_assignees(ex::Expr)::FunctionName
     elseif ex.head == :...
         # Handles splat assignments. e.g. _, y... = 1:5
         args = ex.args
-        union!(Symbol[], Iterators.map(get_assignees, args)...)
+        mapfoldl(get_assignees, union!, args; init=Symbol[])
     else
         @warn "unknown use of `=`. Assignee is unrecognised." ex
         Symbol[]
@@ -373,12 +373,13 @@ function explore_assignment!(ex::Expr, scopestate::ScopeState)::SymbolsState
     global_assignees = get_global_assignees(assignees, scopestate)
 
     # If we are _not_ assigning a global variable, then this symbol hides any global definition with that name
-    push!(scopestate.hiddenglobals, setdiff(assignees, global_assignees)...)
+    union!(scopestate.hiddenglobals, setdiff(assignees, global_assignees))
     assigneesymstate = explore!(ex.args[1], scopestate)
 
-    push!(scopestate.hiddenglobals, global_assignees...)
-    push!(symstate.assignments, global_assignees...)
-    push!(symstate.references, setdiff(assigneesymstate.references, global_assignees)...)
+    union!(scopestate.hiddenglobals, global_assignees)
+    union!(symstate.assignments, global_assignees)
+    union!(symstate.references, setdiff(assigneesymstate.references, global_assignees))
+    union!(symstate.funccalls, filter!(call -> length(call) != 1 || only(call) ∉ global_assignees, assigneesymstate.funccalls))
     filter!(!all_underscores, symstate.references)  # Never record _ as a reference
 
     return symstate
@@ -1347,6 +1348,7 @@ function can_be_function_wrapped(x::Expr)
        x.head === :using ||
        x.head === :import ||
        x.head === :module ||
+       x.head === :incomplete ||
        # Only bail on named functions, but anonymous functions (args[1].head == :tuple) are fine.
        # TODO Named functions INSIDE other functions should be fine too
        (x.head === :function && !Meta.isexpr(x.args[1], :tuple)) ||
diff --git a/src/analysis/Parse.jl b/src/analysis/Parse.jl
index 200b5faf4b..b3ac5162d5 100644
--- a/src/analysis/Parse.jl
+++ b/src/analysis/Parse.jl
@@ -1,4 +1,5 @@
 import .ExpressionExplorer
+import Markdown
 
 "Generate a file name to be given to the parser (will show up in stack traces)."
 pluto_filename(notebook::Notebook, cell::Cell)::String = notebook.path * "#==#" * string(cell.cell_id)
@@ -19,7 +20,7 @@ function parse_custom(notebook::Notebook, cell::Cell)::Expr
     raw = if can_insert_filename
         filename = pluto_filename(notebook, cell)
         ex = Base.parse_input_line(cell.code, filename=filename)
-        if (ex isa Expr) && (ex.head == :toplevel)
+        if Meta.isexpr(ex, :toplevel)
             # if there is more than one expression:
             if count(a -> !(a isa LineNumberNode), ex.args) > 1
                 Expr(:error, "extra token after end of expression\n\nBoundaries: $(expression_boundaries(cell.code))")
@@ -100,12 +101,14 @@ Make some small adjustments to the `expr` to make it work nicely inside a timed,
 3. If `expr` is a `:(=)` expression with a curly assignment, wrap it in a `:const` to allow execution - see https://github.com/fonsp/Pluto.jl/issues/517
 """
 function preprocess_expr(expr::Expr)
-    if expr.head == :toplevel
+    if expr.head === :toplevel
 		Expr(:block, expr.args...)
-    elseif expr.head == :module
+    elseif expr.head === :module
         Expr(:toplevel, expr)
-    elseif expr.head == :(=) && (expr.args[1] isa Expr && expr.args[1].head == :curly)
+    elseif expr.head === :(=) && (expr.args[1] isa Expr && expr.args[1].head == :curly)
         Expr(:const, expr)
+    elseif expr.head === :incomplete
+        Expr(:call, :(PlutoRunner.throw_syntax_error), expr.args...)
     else
         expr
     end
diff --git a/src/analysis/is_just_text.jl b/src/analysis/is_just_text.jl
index f4402a6b2a..38339f68af 100644
--- a/src/analysis/is_just_text.jl
+++ b/src/analysis/is_just_text.jl
@@ -1,12 +1,22 @@
-const md_and_friends = [Symbol("@md_str"), Symbol("@html_str"), :getindex]
+const md_and_friends = [
+	# Text
+	Symbol("@md_str"),
+	Symbol("@html_str"),
+	:getindex,
+]
 
 """Does the cell only contain md"..." and html"..."?
 
 This is used to run these cells first."""
 function is_just_text(topology::NotebookTopology, cell::Cell)::Bool
 	# https://github.com/fonsp/Pluto.jl/issues/209
-	isempty(topology.nodes[cell].definitions) && isempty(topology.nodes[cell].funcdefs_with_signatures) && 
-		topology.nodes[cell].references ⊆ md_and_friends &&
+        node = topology.nodes[cell]
+	((isempty(node.definitions) &&
+		isempty(node.funcdefs_with_signatures) &&
+		node.references ⊆ md_and_friends) ||
+	 (length(node.references) == 2 &&
+		:PlutoRunner in node.references &&
+		Symbol("PlutoRunner.throw_syntax_error") in node.references)) &&
 		no_loops(ExpressionExplorer.maybe_macroexpand(topology.codes[cell].parsedcode; recursive=true))
 end
 
@@ -24,4 +34,4 @@ function no_loops(ex::Expr)
 	end
 end
 
-no_loops(x) = true
\ No newline at end of file
+no_loops(x) = true
diff --git a/src/evaluation/Run.jl b/src/evaluation/Run.jl
index 4a61210162..21f8e1f212 100644
--- a/src/evaluation/Run.jl
+++ b/src/evaluation/Run.jl
@@ -528,6 +528,7 @@ function notebook_differences(from::Notebook, to::Notebook)
 			end
 		end,
 		
+		folded_changed = any(from_cells[id].code_folded != to_cells[id].code_folded for id in keys(from_cells) if haskey(to_cells, id)),
 		order_changed = from.cell_order != to.cell_order,
 		nbpkg_changed = !is_nbpkg_equal(from.nbpkg_ctx, to.nbpkg_ctx),
 	)
@@ -559,16 +560,17 @@ function update_from_file(session::ServerSession, notebook::Notebook; kwargs...)
 	# @show added removed changed
 	
 	cells_changed = !(isempty(added) && isempty(removed) && isempty(changed))
+	folded_changed = d.folded_changed
 	order_changed = d.order_changed
 	nbpkg_changed = d.nbpkg_changed
 		
-	something_changed = cells_changed || order_changed || (include_nbpg && nbpkg_changed)
-	
+	something_changed = cells_changed || folded_changed || order_changed || (include_nbpg && nbpkg_changed)
+
 	if something_changed
 		@info "Reloading notebook from file and applying changes!"
 		notebook.last_hot_reload_time = time()
 	end
-
+	
 	for c in added
 		notebook.cells_dict[c] = just_loaded.cells_dict[c]
 	end
@@ -583,10 +585,10 @@ function update_from_file(session::ServerSession, notebook::Notebook; kwargs...)
 	for c in keys(notebook.cells_dict) ∩ keys(just_loaded.cells_dict)
 		notebook.cells_dict[c].code_folded = just_loaded.cells_dict[c].code_folded
 	end
-	
+
 	notebook.cell_order = just_loaded.cell_order
 	notebook.metadata = just_loaded.metadata
-	
+
 	if include_nbpg && nbpkg_changed
 		@info "nbpkgs not equal" (notebook.nbpkg_ctx isa Nothing) (just_loaded.nbpkg_ctx isa Nothing)
 		
@@ -603,11 +605,11 @@ function update_from_file(session::ServerSession, notebook::Notebook; kwargs...)
 		end
 		notebook.nbpkg_restart_required_msg = "Yes, because the file was changed externally and the embedded Pkg changed."
 	end
-	
+
 	if something_changed
-		update_save_run!(session, notebook, Cell[notebook.cells_dict[c] for c in union(added, changed)]; kwargs...) # this will also update nbpkg
+		update_save_run!(session, notebook, Cell[notebook.cells_dict[c] for c in union(added, changed)]; kwargs...) # this will also update nbpkg if needed
 	end
-	
+
 	return true
 end
 
diff --git a/src/evaluation/WorkspaceManager.jl b/src/evaluation/WorkspaceManager.jl
index 6e25c65da6..f1e732a0f6 100644
--- a/src/evaluation/WorkspaceManager.jl
+++ b/src/evaluation/WorkspaceManager.jl
@@ -7,18 +7,19 @@ import ..Pluto.PkgCompat
 import ..Configuration: CompilerOptions, _merge_notebook_compiler_options, _convert_to_flags
 import ..Pluto.ExpressionExplorer: FunctionName
 import ..PlutoRunner
-import Distributed
+import Malt
+import Malt.Distributed
 
 """
-Contains the Julia process (in the sense of `Distributed.addprocs`) to evaluate code in.
+Contains the Julia process to evaluate code in.
 Each notebook gets at most one `Workspace` at any time, but it can also have no `Workspace`
 (it cannot `eval` code in this case).
 """
 Base.@kwdef mutable struct Workspace
-    pid::Integer
+    worker::Malt.AbstractWorker
     notebook_id::UUID
     discarded::Bool=false
-    remote_log_channel::Distributed.RemoteChannel
+    remote_log_channel::Union{Distributed.RemoteChannel,AbstractChannel}
     module_name::Symbol
     dowork_token::Token=Token()
     nbpkg_was_active::Bool=false
@@ -30,25 +31,19 @@ end
 
 const SN = Tuple{ServerSession, Notebook}
 
+"These expressions get evaluated whenever a new `Workspace` process is created."
+process_preamble() = quote
+    Base.exit_on_sigint(false)
+    include($(project_relative_path(joinpath("src", "runner"), "Loader.jl")))
+    ENV["GKSwstype"] = "nul"
+    ENV["JULIA_REVISE_WORKER_ONLY"] = "1"
+end
+
 const active_workspaces = Dict{UUID,Task}()
 
 "Set of notebook IDs that we will never make a process for again."
 const discarded_workspaces = Set{UUID}()
 
-const Distributed_expr = quote
-    Base.loaded_modules[Base.PkgId(Base.UUID("8ba89e20-285c-5b6f-9357-94700520ee1b"), "Distributed")]
-end
-
-"These expressions get evaluated whenever a new `Workspace` process is created."
-function process_preamble()
-    quote
-        Base.exit_on_sigint(false)
-        include($(project_relative_path(joinpath("src", "runner"), "Loader.jl")))
-        ENV["GKSwstype"] = "nul"
-        ENV["JULIA_REVISE_WORKER_ONLY"] = "1"
-    end
-end
-
 "Create a workspace for the notebook, optionally in the main process."
 function make_workspace((session, notebook)::SN; is_offline_renderer::Bool=false)::Workspace
     workspace_business = is_offline_renderer ? Status.Business(name=:gobble) : Status.report_business_started!(notebook.status_tree, :workspace)
@@ -56,26 +51,22 @@ function make_workspace((session, notebook)::SN; is_offline_renderer::Bool=false
     Status.report_business_planned!(workspace_business, :init_process)
     
     is_offline_renderer || (notebook.process_status = ProcessStatus.starting)
-
-    use_distributed = !is_offline_renderer && session.options.evaluation.workspace_use_distributed
-
-    pid = if use_distributed
-        @debug "Creating workspace process" notebook.path length(notebook.cells)
-        create_workspaceprocess(; 
-            compiler_options=_merge_notebook_compiler_options(notebook, session.options.compiler),
-            status=create_status,
-        )
+    
+    WorkerType = if is_offline_renderer || !session.options.evaluation.workspace_use_distributed
+        Malt.InProcessWorker
+    elseif something(
+        session.options.evaluation.workspace_use_distributed_stdlib, 
+        true
+        # VERSION < v"1.8.0-0"
+    )
+        Malt.DistributedStdlibWorker
     else
-        pid = Distributed.myid()
-        if !(isdefined(Main, :PlutoRunner) && Main.PlutoRunner isa Module)
-            # Make PlutoRunner available in Main, right now it's only defined inside this Pluto module.
-            @eval Main begin
-                PlutoRunner = $(PlutoRunner)
-            end
-        end
-        pid
+        Malt.Worker
     end
     
+    @debug "Creating workspace process" notebook.path length(notebook.cells)
+    worker = create_workspaceprocess(WorkerType; compiler_options=_merge_notebook_compiler_options(notebook, session.options.compiler))
+    
     Status.report_business_finished!(workspace_business, :create_process)
     init_status = Status.report_business_started!(workspace_business, :init_process)
     Status.report_business_started!(init_status, Symbol(1))
@@ -83,33 +74,29 @@ function make_workspace((session, notebook)::SN; is_offline_renderer::Bool=false
     Status.report_business_planned!(init_status, Symbol(3))
     Status.report_business_planned!(init_status, Symbol(4))
 
-    Distributed.remotecall_eval(Main, [pid], session.options.evaluation.workspace_custom_startup_expr)
+    Malt.remote_eval_wait(worker, session.options.evaluation.workspace_custom_startup_expr)
 
-    Distributed.remotecall_eval(Main, [pid], quote
+    Malt.remote_eval_wait(worker, quote
         PlutoRunner.notebook_id[] = $(notebook.notebook_id)
     end)
 
-    remote_log_channel = Core.eval(Main, quote
-        $(Distributed).RemoteChannel(() -> eval(quote
-            channel = Channel{Any}(10)
-            Main.PlutoRunner.setup_plutologger(
-                $($(notebook.notebook_id)), 
-                channel,
-            )
+    remote_log_channel = Malt.worker_channel(worker, quote
+        channel = Channel{Any}(10)
+        Main.PlutoRunner.setup_plutologger(
+            $(notebook.notebook_id),
             channel
-        end), $pid)
+        )
+        channel
     end)
 
-    run_channel = Core.eval(Main, quote
-        $(Distributed).RemoteChannel(() -> eval(:(Main.PlutoRunner.run_channel)), $pid)
-    end)
+    run_channel = Malt.worker_channel(worker, :(Main.PlutoRunner.run_channel))
 
-    module_name = create_emptyworkspacemodule(pid)
+    module_name = create_emptyworkspacemodule(worker)
 
-    original_LOAD_PATH, original_ACTIVE_PROJECT = Distributed.remotecall_eval(Main, pid, :(Base.LOAD_PATH, Base.ACTIVE_PROJECT[]))
+    original_LOAD_PATH, original_ACTIVE_PROJECT = Malt.remote_eval_fetch(worker, :(Base.LOAD_PATH, Base.ACTIVE_PROJECT[]))
 
     workspace = Workspace(;
-        pid,
+        worker,
         notebook_id=notebook.notebook_id,
         remote_log_channel,
         module_name,
@@ -156,20 +143,20 @@ function use_nbpkg_environment((session, notebook)::SN, workspace=nothing)
     workspace.discarded && return
 
     workspace.nbpkg_was_active = enabled
-    if workspace.pid != Distributed.myid()
-        new_LP = enabled ? ["@", "@stdlib"] : workspace.original_LOAD_PATH
-        new_AP = enabled ? PkgCompat.env_dir(notebook.nbpkg_ctx) : workspace.original_ACTIVE_PROJECT
-
-        Distributed.remotecall_eval(Main, [workspace.pid], quote
-            copy!(LOAD_PATH, $(new_LP))
-            Base.ACTIVE_PROJECT[] = $(new_AP)
-        end)
-    else
-        # TODO
+    if workspace.worker isa Malt.InProcessWorker
+        # Not supported
+        return
     end
+    new_LP = enabled ? ["@", "@stdlib"] : workspace.original_LOAD_PATH
+    new_AP = enabled ? PkgCompat.env_dir(notebook.nbpkg_ctx) : workspace.original_ACTIVE_PROJECT
+
+    Malt.remote_eval_wait(workspace.worker, quote
+        copy!(LOAD_PATH, $(new_LP))
+        Base.ACTIVE_PROJECT[] = $(new_AP)
+    end)
 end
 
-function start_relaying_self_updates((session, notebook)::SN, run_channel::Distributed.RemoteChannel)
+function start_relaying_self_updates((session, notebook)::SN, run_channel)
     while true
         try
             next_run_uuid = take!(run_channel)
@@ -185,7 +172,7 @@ function start_relaying_self_updates((session, notebook)::SN, run_channel::Distr
     end
 end
 
-function start_relaying_logs((session, notebook)::SN, log_channel::Distributed.RemoteChannel)
+function start_relaying_logs((session, notebook)::SN, log_channel)
     update_throttled, flush_throttled = Pluto.throttled(0.1) do
         Pluto.send_notebook_changes!(Pluto.ClientRequest(; session, notebook))
     end
@@ -230,6 +217,10 @@ function start_relaying_logs((session, notebook)::SN, log_channel::Distributed.R
 
             @assert !isnothing(display_cell)
 
+            # this handles the use of published_to_js inside logs: objects that were newly published during the rendering of the log args.
+            merge!(display_cell.published_objects, next_log["new_published_objects"])
+            delete!(next_log, "new_published_objects")
+
             push!(display_cell.logs, next_log)
             Pluto.@asynclog update_throttled()
         catch e
@@ -252,7 +243,7 @@ end
 function bump_workspace_module(session_notebook::SN)
     workspace = get_workspace(session_notebook)
     old_name = workspace.module_name
-    new_name = workspace.module_name = create_emptyworkspacemodule(workspace.pid)
+    new_name = workspace.module_name = create_emptyworkspacemodule(workspace.worker)
 
     old_name, new_name
 end
@@ -260,21 +251,21 @@ end
 function get_bond_names(session_notebook::SN, cell_id)
     workspace = get_workspace(session_notebook)
 
-    Distributed.remotecall_eval(Main, workspace.pid, quote
-        PlutoRunner.get_bond_names($cell_id)
+    Malt.remote_eval_fetch(workspace.worker, quote
+    PlutoRunner.get_bond_names($cell_id)
     end)
 end
 
 function possible_bond_values(session_notebook::SN, n::Symbol; get_length::Bool=false)
     workspace = get_workspace(session_notebook)
 
-    Distributed.remotecall_eval(Main, workspace.pid, quote
+    Malt.remote_eval_fetch(workspace.worker, quote
         PlutoRunner.possible_bond_values($(QuoteNode(n)); get_length=$(get_length))
     end)
 end
 
-function create_emptyworkspacemodule(pid::Integer)::Symbol
-    Distributed.remotecall_eval(Main, pid, quote
+function create_emptyworkspacemodule(worker::Malt.AbstractWorker)::Symbol
+    Malt.remote_eval_fetch(worker, quote
         PlutoRunner.increment_current_module()
     end)
 end
@@ -282,33 +273,41 @@ end
 # NOTE: this function only start a worker process using given
 # compiler options, it does not resolve paths for notebooks
 # compiler configurations passed to it should be resolved before this
-function create_workspaceprocess(; compiler_options=CompilerOptions(), status::Status.Business=Business())::Integer
-    
-    Status.report_business_started!(status, Symbol(1))
-    Status.report_business_planned!(status, Symbol(2))
-    # run on proc 1 in case Pluto is being used inside a notebook process
-    # Workaround for "only process 1 can add/remove workers"
-    pid = Distributed.remotecall_eval(Main, 1, quote
-        $(Distributed_expr).addprocs(1; exeflags=$(_convert_to_flags(compiler_options))) |> first
-    end)
-    
-    Status.report_business_finished!(status, Symbol(1))
-    Status.report_business_started!(status, Symbol(2))
+function create_workspaceprocess(WorkerType; compiler_options=CompilerOptions(), status::Status.Business=Status.Business())::Malt.AbstractWorker
 
-    Distributed.remotecall_eval(Main, [pid], process_preamble())
-
-    # so that we NEVER break the workspace with an interrupt 🤕
-    @async Distributed.remotecall_eval(Main, [pid], quote
-        while true
-            try
-                wait()
-            catch end
+    if WorkerType === Malt.InProcessWorker
+        worker = WorkerType()
+        
+        if !(isdefined(Main, :PlutoRunner) && Main.PlutoRunner isa Module)
+            # we make PlutoRunner available in Main, right now it's only defined inside this Pluto module.
+            Malt.remote_eval_wait(Main, worker, quote
+                PlutoRunner = $(PlutoRunner)
+            end)
         end
-    end)
+    else
+            
+        Status.report_business_started!(status, Symbol(1))
+        Status.report_business_planned!(status, Symbol(2))
+        
+        worker = WorkerType(; exeflags=_convert_to_flags(compiler_options))
+            
+        Status.report_business_finished!(status, Symbol(1))
+        Status.report_business_started!(status, Symbol(2))
+        
+        Malt.remote_eval_wait(worker, process_preamble())
+    
+        # so that we NEVER break the workspace with an interrupt 🤕
+        Malt.remote_eval(worker, quote
+            while true
+                try
+                    wait()
+                catch end
+            end
+        end)
+    end
     
     Status.report_business_finished!(status)
-
-    pid
+    worker
 end
 
 """
@@ -345,28 +344,16 @@ function unmake_workspace(session_notebook::SN; async::Bool=false, verbose::Bool
     workspace.discarded = true
     allow_restart || push!(discarded_workspaces, notebook.notebook_id)
 
-    if workspace.pid != Distributed.myid()
-        filter!(p -> fetch(p.second).pid != workspace.pid, active_workspaces)
-        t = @async begin
-            interrupt_workspace(workspace; verbose=false)
-            # run on proc 1 in case Pluto is being used inside a notebook process
-            # Workaround for "only process 1 can add/remove workers"
-            Distributed.remotecall_eval(Main, 1, quote
-                $(Distributed_expr).rmprocs($(workspace.pid))
-            end)
-        end
-        async || wait(t)
-    else
-        if !isready(workspace.dowork_token)
-            @error "Cannot unmake a workspace running inside the same process: the notebook is still running."
-        elseif verbose
-            @warn "Cannot unmake a workspace running inside the same process: the notebook might still be running. If you are sure that your code is not running the notebook async, then you can use the `verbose=false` keyword argument to disable this message."
-        end
+    filter!(p -> fetch(p.second).worker != workspace.worker, active_workspaces)
+    t = @async begin
+        interrupt_workspace(workspace; verbose=false)
+        Malt.stop(workspace.worker)
     end
+    async || wait(t)
     nothing
 end
 
-function distributed_exception_result(ex::Base.IOError, workspace::Workspace)
+function workspace_exception_result(ex::Union{Base.IOError, Malt.TerminatedWorkerException, Distributed.ProcessExitedException}, workspace::Workspace)
     (
         output_formatted=PlutoRunner.format_output(CapturedException(ex, [])),
         errored=true,
@@ -378,12 +365,11 @@ function distributed_exception_result(ex::Base.IOError, workspace::Workspace)
     )
 end
 
-function distributed_exception_result(exs::CompositeException, workspace::Workspace)
-    ex = first(exs.exceptions)
+workspace_exception_result(exs::CompositeException, workspace::Workspace) = workspace_exception_result(first(exs.exceptions), workspace)
 
-    if ex isa Distributed.RemoteException &&
-        ex.pid == workspace.pid &&
-        ex.captured.ex isa InterruptException
+function workspace_exception_result(ex::Exception, workspace::Workspace)
+    if ex isa InterruptException || (ex isa Malt.RemoteException && occursin("InterruptException", ex.message))
+        @info "Found an interrupt!" ex
         (
             output_formatted=PlutoRunner.format_output(CapturedException(InterruptException(), [])),
             errored=true,
@@ -393,23 +379,13 @@ function distributed_exception_result(exs::CompositeException, workspace::Worksp
             published_objects=Dict{String,Any}(),
             has_pluto_hook_features=false,
         )
-    elseif ex isa Distributed.ProcessExitedException
-        (
-            output_formatted=PlutoRunner.format_output(CapturedException(exs, [])),
-            errored=true,
-            interrupted=true,
-            process_exited=true && !workspace.discarded, # don't report a process exit if the workspace was discarded on purpose
-            runtime=nothing,
-            published_objects=Dict{String,Any}(),
-            has_pluto_hook_features=false,
-        )
     else
         @error "Unkown error during eval_format_fetch_in_workspace" ex
         (
-            output_formatted=PlutoRunner.format_output(CapturedException(exs, [])),
+            output_formatted=PlutoRunner.format_output(CapturedException(ex, [])),
             errored=true,
             interrupted=true,
-            process_exited=false,
+            process_exited=!Malt.isrunning(workspace.worker) && !workspace.discarded, # don't report a process exit if the workspace was discarded on purpose
             runtime=nothing,
             published_objects=Dict{String,Any}(),
             has_pluto_hook_features=false,
@@ -438,14 +414,10 @@ function eval_format_fetch_in_workspace(
 )::PlutoRunner.FormattedCellResult
 
     workspace = get_workspace(session_notebook)
-
-    is_on_this_process = workspace.pid == Distributed.myid()
+    is_on_this_process = workspace.worker isa Malt.InProcessWorker
 
     # if multiple notebooks run on the same process, then we need to `cd` between the different notebook paths
     if session_notebook isa Tuple
-        if is_on_this_process
-            cd_workspace(workspace, session_notebook[2].path)
-        end
         use_nbpkg_environment(session_notebook, workspace)
     end
 
@@ -455,8 +427,7 @@ function eval_format_fetch_in_workspace(
     take!(workspace.dowork_token)
     workspace.has_executed_effectful_code |= code_is_effectful
     early_result = try
-        # Use [pid] instead of pid to prevent fetching output
-        Distributed.remotecall_eval(Main, [workspace.pid], quote
+        Malt.remote_eval_wait(workspace.worker, quote
             PlutoRunner.run_expression(
                 getfield(Main, $(QuoteNode(workspace.module_name))),
                 $(QuoteNode(expr)),
@@ -473,7 +444,7 @@ function eval_format_fetch_in_workspace(
     catch e
         # Don't use a `finally` because the token needs to be back asap for the interrupting code to pick it up.
         put!(workspace.dowork_token)
-        distributed_exception_result(e, workspace)
+        workspace_exception_result(e, workspace)
     end
 
     if early_result === nothing
@@ -487,7 +458,7 @@ end
 function eval_in_workspace(session_notebook::Union{SN,Workspace}, expr)
     workspace = get_workspace(session_notebook)
 
-    Distributed.remotecall_eval(Main, [workspace.pid], quote
+    Malt.remote_eval_wait(workspace.worker, quote
         Core.eval($(workspace.module_name), $(QuoteNode(expr)))
     end)
     nothing
@@ -508,7 +479,7 @@ function format_fetch_in_workspace(
     # we format the cell output on the worker, and fetch the formatted output.
     withtoken(workspace.dowork_token) do
         try
-            Distributed.remotecall_eval(Main, workspace.pid, quote
+            Malt.remote_eval_fetch(workspace.worker, quote
                 PlutoRunner.formatted_result_of(
                     $(workspace.notebook_id),
                     $cell_id,
@@ -520,7 +491,7 @@ function format_fetch_in_workspace(
                 )
             end)
         catch e
-            distributed_exception_result(CompositeException([e]), workspace)
+            workspace_exception_result(CompositeException([e]), workspace)
         end
     end
 end
@@ -528,7 +499,7 @@ end
 function collect_soft_definitions(session_notebook::SN, modules::Set{Expr})
     workspace = get_workspace(session_notebook)
 
-    Distributed.remotecall_eval(Main, workspace.pid, quote
+    Malt.remote_eval_fetch(workspace.worker, quote
         PlutoRunner.collect_soft_definitions($(workspace.module_name), $modules)
     end)
 end
@@ -537,7 +508,7 @@ function macroexpand_in_workspace(session_notebook::SN, macrocall, cell_id, modu
     workspace = get_workspace(session_notebook)
     module_name = module_name === Symbol("") ? workspace.module_name : module_name
 
-    Distributed.remotecall_eval(Main, workspace.pid, quote
+    Malt.remote_eval_fetch(workspace.worker, quote
         try
             (true, PlutoRunner.try_macroexpand($(module_name), $(workspace.notebook_id), $(cell_id), $(macrocall |> QuoteNode); capture_stdout=$(capture_stdout)))
         catch error
@@ -557,7 +528,7 @@ end
 function eval_fetch_in_workspace(session_notebook::Union{SN,Workspace}, expr)
     workspace = get_workspace(session_notebook)
 
-    Distributed.remotecall_eval(Main, workspace.pid, quote
+    Malt.remote_eval_fetch(workspace.worker, quote
         Core.eval($(workspace.module_name), $(QuoteNode(expr)))
     end)
 end
@@ -565,14 +536,14 @@ end
 function do_reimports(session_notebook::Union{SN,Workspace}, module_imports_to_move::Set{Expr})
     workspace = get_workspace(session_notebook)
 
-    Distributed.remotecall_eval(Main, [workspace.pid], quote
+    Malt.remote_eval_wait(workspace.worker, quote
         PlutoRunner.do_reimports($(workspace.module_name), $module_imports_to_move)
     end)
 end
 
 """
-Move variables to a new module. Variables to be 'deleted' will not be moved to
-the new module, making them unavailable.
+Move variables to a new module. A given set of variables to be 'deleted' will
+not be moved to the new module, making them unavailable.
 """
 function move_vars(
     session_notebook::Union{SN,Workspace},
@@ -589,7 +560,7 @@ function move_vars(
     workspace = get_workspace(session_notebook)
     new_workspace_name = something(new_workspace_name, workspace.module_name)
 
-    Distributed.remotecall_eval(Main, [workspace.pid], quote
+    Malt.remote_eval_wait(workspace.worker, quote
         PlutoRunner.move_vars(
             $(QuoteNode(old_workspace_name)),
             $(QuoteNode(new_workspace_name)),
@@ -678,11 +649,6 @@ function interrupt_workspace(session_notebook::Union{SN,Workspace}; verbose=true
         return false
     end
 
-    if workspace.pid == Distributed.myid()
-        verbose && @warn """Cells in this workspace can't be stopped, because it is not running in a separate workspace. Use `ENV["PLUTO_WORKSPACE_USE_DISTRIBUTED"]` to control whether future workspaces are generated in a separate process."""
-        return false
-    end
-
     if isready(workspace.dowork_token)
         verbose && @info "Tried to stop idle workspace - ignoring."
         return true
@@ -693,8 +659,8 @@ function interrupt_workspace(session_notebook::Union{SN,Workspace}; verbose=true
     # TODO: this will also kill "pending" evaluations, and any evaluations started within 100ms of the kill. A global "evaluation count" would fix this.
     # TODO: listen for the final words of the remote process on stdout/stderr: "Force throwing a SIGINT"
     try
-        verbose && @info "Sending interrupt to process $(workspace.pid)"
-        Distributed.interrupt(workspace.pid)
+        verbose && @info "Sending interrupt to process $(workspace.worker)"
+        Malt.interrupt(workspace.worker)
 
         if poll(() -> isready(workspace.dowork_token), 5.0, 5/100)
             verbose && println("Cell interrupted!")
@@ -705,7 +671,7 @@ function interrupt_workspace(session_notebook::Union{SN,Workspace}; verbose=true
         while !isready(workspace.dowork_token)
             for _ in 1:5
                 verbose && print(" 🔥 ")
-                Distributed.interrupt(workspace.pid)
+                Malt.interrupt(workspace.worker)
                 sleep(0.18)
                 if isready(workspace.dowork_token)
                     break
diff --git a/src/packages/PkgCompat.jl b/src/packages/PkgCompat.jl
index 250b275359..f0e857fc00 100644
--- a/src/packages/PkgCompat.jl
+++ b/src/packages/PkgCompat.jl
@@ -258,7 +258,7 @@ _stdlibs() = try
 catch e
 	@warn "Pkg compat: failed to load standard libraries." exception=(e,catch_backtrace())
 
-	String["CRC32c", "Future", "Sockets", "MbedTLS_jll", "Random", "ArgTools", "libLLVM_jll", "GMP_jll", "Pkg", "Serialization", "LibSSH2_jll", "SHA", "OpenBLAS_jll", "REPL", "LibUV_jll", "nghttp2_jll", "Unicode", "Profile", "SparseArrays", "LazyArtifacts", "CompilerSupportLibraries_jll", "Base64", "Artifacts", "PCRE2_jll", "Printf", "p7zip_jll", "UUIDs", "Markdown", "TOML", "OpenLibm_jll", "Test", "MPFR_jll", "Mmap", "SuiteSparse", "LibGit2", "LinearAlgebra", "Logging", "NetworkOptions", "LibGit2_jll", "LibOSXUnwind_jll", "Dates", "LibUnwind_jll", "Libdl", "LibCURL_jll", "dSFMT_jll", "Distributed", "InteractiveUtils", "Downloads", "SharedArrays", "SuiteSparse_jll", "LibCURL", "Statistics", "Zlib_jll", "FileWatching", "DelimitedFiles", "Tar", "MozillaCACerts_jll"]
+	String["ArgTools", "Artifacts", "Base64", "CRC32c", "CompilerSupportLibraries_jll", "Dates", "DelimitedFiles", "Distributed", "Downloads", "FileWatching", "Future", "GMP_jll", "InteractiveUtils", "LLD_jll", "LLVMLibUnwind_jll", "LazyArtifacts", "LibCURL", "LibCURL_jll", "LibGit2", "LibGit2_jll", "LibOSXUnwind_jll", "LibSSH2_jll", "LibUV_jll", "LibUnwind_jll", "Libdl", "LinearAlgebra", "Logging", "MPFR_jll", "Markdown", "MbedTLS_jll", "Mmap", "MozillaCACerts_jll", "NetworkOptions", "OpenBLAS_jll", "OpenLibm_jll", "PCRE2_jll", "Pkg", "Printf", "Profile", "REPL", "Random", "SHA", "Serialization", "SharedArrays", "Sockets", "SparseArrays", "Statistics", "SuiteSparse", "SuiteSparse_jll", "TOML", "Tar", "Test", "UUIDs", "Unicode", "Zlib_jll", "dSFMT_jll", "libLLVM_jll", "libblastrampoline_jll", "nghttp2_jll", "p7zip_jll"]
 end
 
 # ⚠️ Internal API with fallback
diff --git a/src/runner/PlutoRunner.jl b/src/runner/PlutoRunner.jl
index 5e3b49e81f..cf252733ab 100644
--- a/src/runner/PlutoRunner.jl
+++ b/src/runner/PlutoRunner.jl
@@ -1,17 +1,21 @@
 # Will be evaluated _inside_ the workspace process.
 
-# Pluto does most things on process 1 (the server), and it uses little workspace processes to evaluate notebook code in.
-# These baby processes don't import Pluto, they only import this module. Functions from this module are called by WorkspaceManager.jl via Distributed
+# Pluto does most things on the server, but it uses worker processes to evaluate notebook code in.
+# These processes don't import Pluto, they only import this module.
+# Functions from this module are called by WorkspaceManager.jl via Malt.
 
-# So when reading this file, pretend that you are living in process 2, and you are communicating with Pluto's server, who lives in process 1.
+# When reading this file, pretend that you are living in a worker process,
+# and you are communicating with Pluto's server, who lives in the main process.
 # The package environment that this file is loaded with is the NotebookProcessProject.toml file in this directory.
 
 # SOME EXTRA NOTES
 
 # 1. The entire PlutoRunner should be a single file.
-# 2. We restrict the communication between this PlutoRunner and the Pluto server to only use *Base Julia types*, like `String`, `Dict`, `NamedTuple`, etc. 
+# 2. Restrict the communication between this PlutoRunner and the Pluto server to only use *Base Julia types*, like `String`, `Dict`, `NamedTuple`, etc. 
 
-# These restriction are there to allow flexibility in the way that this file is loaded on a runner process, which is something that we might want to change in the future, like when we make the transition to our own Distributed.
+# These restriction are there to allow flexibility in the way that this file is
+# loaded on a runner process, which is something that we might want to change
+# in the future.
 
 module PlutoRunner
 
@@ -21,7 +25,6 @@ import InteractiveUtils
 
 using Markdown
 import Markdown: html, htmlinline, LaTeX, withtag, htmlesc
-import Distributed
 import Base64
 import FuzzyCompletions: Completion, BslashCompletion, ModuleCompletion, PropertyCompletion, FieldCompletion, PathCompletion, DictCompletion, completions, completion_text, score
 import Base: show, istextmime
@@ -32,7 +35,7 @@ import REPL
 
 export @bind
 
-# This is not a struct to make it easier to pass these objects between distributed processes.
+# This is not a struct to make it easier to pass these objects between processes.
 const MimedOutput = Tuple{Union{String,Vector{UInt8},Dict{Symbol,Any}},MIME}
 
 const ObjectID = typeof(objectid("hello computer"))
@@ -273,7 +276,7 @@ function try_macroexpand(mod::Module, notebook_id::UUID, cell_id::UUID, expr; ca
     pop!(cell_expanded_exprs, cell_id, nothing)
 
     # Remove toplevel block, as that screws with the computer and everything
-    expr_not_toplevel = if expr.head == :toplevel || expr.head == :block
+    expr_not_toplevel = if Meta.isexpr(expr, (:toplevel, :block))
         Expr(:block, expr.args...)
     else
         @warn "try_macroexpand expression not :toplevel or :block" expr
@@ -671,7 +674,7 @@ Notebook code does run in `Main` - it runs in workspace modules. Every time that
 
 The trick boils down to two things:
 1. When we create a new workspace module, we move over some of the global from the old workspace. (But not the ones that we want to 'delete'!)
-2. If a function used to be defined, but now we want to delete it, then we go through the method table of that function and snoop out all methods that we defined by us, and not by another package. This is how we reverse extending external functions. For example, if you run a cell with `Base.sqrt(s::String) = "the square root of" * s`, and then delete that cell, then you can still call `sqrt(1)` but `sqrt("one")` will err. Cool right!
+2. If a function used to be defined, but now we want to delete it, then we go through the method table of that function and snoop out all methods that were defined by us, and not by another package. This is how we reverse extending external functions. For example, if you run a cell with `Base.sqrt(s::String) = "the square root of" * s`, and then delete that cell, then you can still call `sqrt(1)` but `sqrt("one")` will err. Cool right!
 """
 function move_vars(
     old_workspace_name::Symbol,
@@ -878,7 +881,7 @@ const table_column_display_limit_increase = 30
 
 const tree_display_extra_items = Dict{UUID,Dict{ObjectDimPair,Int64}}()
 
-# This is not a struct to make it easier to pass these objects between distributed processes.
+# This is not a struct to make it easier to pass these objects between processes.
 const FormattedCellResult = NamedTuple{(:output_formatted, :errored, :interrupted, :process_exited, :runtime, :published_objects, :has_pluto_hook_features),Tuple{PlutoRunner.MimedOutput,Bool,Bool,Bool,Union{UInt64,Nothing},Dict{String,Any},Bool}}
 
 function formatted_result_of(
@@ -908,7 +911,13 @@ function formatted_result_of(
     output_formatted = if (!ends_with_semicolon || errored)
         logger = get!(() -> PlutoCellLogger(notebook_id, cell_id), pluto_cell_loggers, cell_id)
         with_logger_and_io_to_logs(logger; capture_stdout, stdio_loglevel=stdout_log_level) do
-            format_output(ans; context=IOContext(default_iocontext, :extra_items=>extra_items, :module => workspace))
+            format_output(ans; context=IOContext(
+            default_iocontext, 
+            :extra_items=>extra_items, 
+            :module => workspace,
+            :pluto_notebook_id => notebook_id,
+            :pluto_cell_id => cell_id,
+        ))
         end
     else
         ("", MIME"text/plain"())
@@ -972,6 +981,7 @@ const default_iocontext = IOContext(devnull,
     :displaysize => (18, 88), 
     :is_pluto => true, 
     :pluto_supported_integration_features => supported_integration_features,
+    :pluto_published_to_js => (io, x) -> core_published_to_js(io, x),
 )
 
 const default_stdout_iocontext = IOContext(devnull, 
@@ -1023,7 +1033,177 @@ format_output(::Nothing; context=default_iocontext) = ("", MIME"text/plain"())
 "Downstream packages can set this to false to obtain unprettified stack traces."
 const PRETTY_STACKTRACES = Ref(true)
 
+# @codemirror/lint has only three levels
+function convert_julia_syntax_level(level)
+    level == :error   ? "error" :
+    level == :warning ? "warning" : "info"
+end
+
+"""
+    map_byte_range_to_utf16_codepoints(s::String, start_byte::Int, end_byte::Int)::Tuple{Int,Int}
+
+Taken from `Base.transcode(::Type{UInt16}, src::Vector{UInt8})`
+but without line constraints. It also does not support invalid
+UTF-8 encoding which `String` should never be anyway.
+
+This maps the given raw byte range `(start_byte, end_byte)` range to UTF-16 codepoints indices.
+
+The resulting range can then be used by code-mirror on the frontend, quoting from the code-mirror docs:
+
+> Character positions are counted from zero, and count each line break and UTF-16 code unit as one unit.
+
+Examples:
+```julia
+                                           123
+                                             vv
+julia> map_byte_range_to_utf16_codepoints("abc", 2, 3)
+(2, 3)
+
+                                           1122
+                                           v   v
+julia> map_byte_range_to_utf16_codepoints("🍕🍕", 1, 8)
+(1, 4)
+
+                                           11233
+                                           v  v
+julia> map_byte_range_to_utf16_codepoints("🍕c🍕", 1, 5)
+(1, 3)
+```
+"""
+function map_byte_range_to_utf16_codepoints(s, start_byte, end_byte)
+    invalid_utf8() = error("invalid UTF-8 string")
+    codeunit(s) == UInt8 || invalid_utf8()
+
+    i, n = 1, ncodeunits(s)
+    u16 = 0
+
+    from, to = -1, -1
+    a = codeunit(s, 1)
+    while true
+        if i == start_byte
+            from = u16
+        end
+        if i == end_byte
+            to = u16
+            break
+        end
+        if i < n && -64 <= a % Int8 <= -12 # multi-byte character
+            i += 1
+            b = codeunit(s, i)
+            if -64 <= (b % Int8) || a == 0xf4 && 0x8f < b
+                # invalid UTF-8 (non-continuation of too-high code point)
+                invalid_utf8()
+            elseif a < 0xe0 # 2-byte UTF-8
+                if i == start_byte
+                    from = u16
+                end
+                if i == end_byte
+                    to = u16
+                    break
+                end
+            elseif i < n # 3/4-byte character
+                i += 1
+                c = codeunit(s, i)
+                if -64 <= (c % Int8) # invalid UTF-8 (non-continuation)
+                    invalid_utf8()
+                elseif a < 0xf0 # 3-byte UTF-8
+                    if i == start_byte
+                        from = u16
+                    end
+                    if i == end_byte
+                        to = u16
+                        break
+                    end
+                elseif i < n
+                    i += 1
+                    d = codeunit(s, i)
+                    if -64 <= (d % Int8) # invalid UTF-8 (non-continuation)
+                        invalid_utf8()
+                    elseif a == 0xf0 && b < 0x90 # overlong encoding
+                        invalid_utf8()
+                    else # 4-byte UTF-8 && 2 codeunits UTF-16
+                        u16 += 1
+                        if i == start_byte
+                            from = u16
+                        end
+                        if i == end_byte
+                            to = u16
+                            break
+                        end
+                    end
+                else # too short
+                    invalid_utf8()
+                end
+            else # too short
+                invalid_utf8()
+            end
+        else
+            # ASCII or invalid UTF-8 (continuation byte or too-high code point)
+        end
+        u16 += 1
+        if i >= n
+            break
+        end
+        i += 1
+        a = codeunit(s, i)
+    end
+
+    if from == -1
+        from = u16
+    end
+    if to == -1
+        to = u16
+    end
+
+    return (from, to)
+end
+
+function convert_diagnostic_to_dict(source, diag)
+    code = source.code
+
+    # JuliaSyntax uses `last_byte < first_byte` to signal an empty range.
+    # https://github.com/JuliaLang/JuliaSyntax.jl/blob/97e2825c68e770a3f56f0ec247deda1a8588070c/src/diagnostics.jl#L67-L75
+    # it references the byte range as such: `source[first_byte:last_byte]` whereas codemirror
+    # is non inclusive, therefore we move the `last_byte` to the next valid character in the string,
+    # an empty range then becomes `from == to`, also JuliaSyntax is one based whereas code-mirror is zero-based
+    # but this is handled in `map_byte_range_to_utf16_codepoints` with `u16 = 0` initially.
+    first_byte = min(diag.first_byte, lastindex(code) + 1)
+    last_byte = min(nextind(code, diag.last_byte), lastindex(code) + 1)
+
+    from, to = map_byte_range_to_utf16_codepoints(code, first_byte, last_byte)
+
+    Dict(:from => from,
+         :to => to,
+         :message => diag.message,
+         :source => "JuliaSyntax.jl",
+         :line => first(Base.JuliaSyntax.source_location(source, diag.first_byte)),
+         :severity => convert_julia_syntax_level(diag.level))
+end
+
+function convert_parse_error_to_dict(ex)
+   Dict(
+       :source => ex.source.code,
+       :diagnostics => [
+           convert_diagnostic_to_dict(ex.source, diag)
+           for diag in ex.diagnostics
+       ]
+   )
+end
+
+function throw_syntax_error(@nospecialize(syntax_err))
+    syntax_err isa String && (syntax_err = "syntax: $syntax_err")
+    syntax_err isa Exception || (syntax_err = ErrorException(syntax_err))
+    throw(syntax_err)
+end
+
+const has_julia_syntax = isdefined(Base, :JuliaSyntax) && fieldcount(Base.Meta.ParseError) == 2
+
 function format_output(val::CapturedException; context=default_iocontext)
+    if has_julia_syntax && val.ex isa Base.Meta.ParseError && val.ex.detail isa Base.JuliaSyntax.ParseError
+        dict = convert_parse_error_to_dict(val.ex.detail)
+        return dict, MIME"application/vnd.pluto.parseerror+object"()
+    end
+
     stacktrace = if PRETTY_STACKTRACES[]
         ## We hide the part of the stacktrace that belongs to Pluto's evalling of user code.
         stack = [s for (s, _) in val.processed_bt]
@@ -1245,7 +1425,7 @@ function array_prefix(@nospecialize(x::Vector{<:Any}))
 end
 
 function array_prefix(@nospecialize(x))
-    original = sprint(Base.showarg, x, false)
+    original = sprint(Base.showarg, x, false; context=:limit => true)
     string(lstrip(original, ':'), ": ")::String
 end
 
@@ -1494,17 +1674,29 @@ const integrations = Integration[
         id = Base.PkgId(Base.UUID(reinterpret(UInt128, codeunits("Paul Berg Berlin")) |> first), "AbstractPlutoDingetjes"),
         code = quote
             @assert v"1.0.0" <= AbstractPlutoDingetjes.MY_VERSION < v"2.0.0"
-            initial_value_getter_ref[] = AbstractPlutoDingetjes.Bonds.initial_value
-            transform_value_ref[] = AbstractPlutoDingetjes.Bonds.transform_value
-            possible_bond_values_ref[] = AbstractPlutoDingetjes.Bonds.possible_values
-
-            push!(supported_integration_features,
+            
+            supported!(xs...) = push!(supported_integration_features, xs...)
+            
+            # don't need feature checks for these because they existed in every version of AbstractPlutoDingetjes:
+            supported!(
                 AbstractPlutoDingetjes,
                 AbstractPlutoDingetjes.Bonds,
                 AbstractPlutoDingetjes.Bonds.initial_value,
                 AbstractPlutoDingetjes.Bonds.transform_value,
                 AbstractPlutoDingetjes.Bonds.possible_values,
             )
+            initial_value_getter_ref[] = AbstractPlutoDingetjes.Bonds.initial_value
+            transform_value_ref[] = AbstractPlutoDingetjes.Bonds.transform_value
+            possible_bond_values_ref[] = AbstractPlutoDingetjes.Bonds.possible_values
+            
+            # feature checks because these were added in a later release of AbstractPlutoDingetjes
+            if isdefined(AbstractPlutoDingetjes, :Display)
+                supported!(AbstractPlutoDingetjes.Display)
+                if isdefined(AbstractPlutoDingetjes.Display, :published_to_js)
+                    supported!(AbstractPlutoDingetjes.Display.published_to_js)
+                end
+            end
+
         end,
     ),
     Integration(
@@ -2003,15 +2195,15 @@ function possible_bond_values(s::Symbol; get_length::Bool=false)
             try
                 length(possible_values)
             catch
-                length(make_distributed_serializable(possible_values))
+                length(make_serializable(possible_values))
             end : 
-            make_distributed_serializable(possible_values)
+            make_serializable(possible_values)
     end
 end
 
-make_distributed_serializable(x::Any) = x
-make_distributed_serializable(x::Union{AbstractVector,AbstractSet,Base.Generator}) = collect(x)
-make_distributed_serializable(x::Union{Vector,Set,OrdinalRange}) = x
+make_serializable(x::Any) = x
+make_serializable(x::Union{AbstractVector,AbstractSet,Base.Generator}) = collect(x)
+make_serializable(x::Union{Vector,Set,OrdinalRange}) = x
 
 
 """
@@ -2125,72 +2317,48 @@ end"""
 """
 const currently_running_cell_id = Ref{UUID}(uuid4())
 
-function _publish(x, id_start)::String
+function core_published_to_js(io, x)
     assertpackable(x)
+
+    id_start = objectid2str(x)
+    
+    _notebook_id = get(io, :pluto_notebook_id, notebook_id[])::UUID
+    _cell_id = get(io, :pluto_cell_id, currently_running_cell_id[])::UUID
     
-    id = string(notebook_id[], "/", currently_running_cell_id[], "/", id_start)
-    d = get!(Dict{String,Any}, cell_published_objects, currently_running_cell_id[])
+    # The unique identifier of this object
+    id = "$_notebook_id/$id_start"
+    
+    d = get!(Dict{String,Any}, cell_published_objects, _cell_id)
     d[id] = x
-    return id
+    
+    write(io, "/* See the documentation for AbstractPlutoDingetjes.Display.published_to_js */ getPublishedObject(\"$(id)\")")
+    
+    return nothing
 end
 
-_publish(x) = _publish(x, objectid2str(x))
-
-# TODO? Possibly move this to it's own package, with fallback that actually msgpack?
-# ..... Ideally we'd make this require `await` on the javascript side too...
-Base.@kwdef struct PublishedToJavascript
-    published_id
-    cell_id
+# TODO: This is the deprecated old function. Remove me at some point.
+struct PublishedToJavascript
+    published_object
 end
 function Base.show(io::IO, ::MIME"text/javascript", published::PublishedToJavascript)
-    if published.cell_id != currently_running_cell_id[]
-        error("Showing result from PlutoRunner.publish_to_js() in a cell different from where it was created, not (yet?) supported.")
-    end
-    write(io, "/* See the documentation for PlutoRunner.publish_to_js */ getPublishedObject(\"$(published.published_id)\")")
+    core_published_to_js(io, published.published_object)
 end
 Base.show(io::IO, ::MIME"text/plain", published::PublishedToJavascript) = show(io, MIME("text/javascript"), published)    
 Base.show(io::IO, published::PublishedToJavascript) = show(io, MIME("text/javascript"), published)    
 
-"""
-    publish_to_js(x)
-
-Make the object `x` available to the JS runtime of this cell. The returned string is a JS command that, when executed in this cell's output, gives the object.
-
-!!! warning
-
-    This function is not yet public API, it will become public in the next weeks. Only use for experiments.
-
-# Example
-```julia
-let
-    x = Dict(
-        "data" => rand(Float64, 20),
-        "name" => "juliette",
-    )
+# TODO: This is the deprecated old function. Remove me at some point.
+function publish_to_js(x)
+    @warn "Deprecated, use `AbstractPlutoDingetjes.Display.published_to_js(x)` instead of `PlutoRunner.publish_to_js(x)`."
 
-    HTML("\""
-    <script>
-    // we interpolate into JavaScript:
-    const x = \$(PlutoRunner.publish_to_js(x))
-
-    console.log(x.name, x.data)
-    </script>
-    "\"")
-end
-```
-"""
-function publish_to_js(args...)
-    PublishedToJavascript(
-        published_id=_publish(args...),
-        cell_id=currently_running_cell_id[],
-    )
+    assertpackable(x)
+    PublishedToJavascript(x)
 end
 
 const Packable = Union{Nothing,Missing,String,Symbol,Int64,Int32,Int16,Int8,UInt64,UInt32,UInt16,UInt8,Float32,Float64,Bool,MIME,UUID,DateTime}
-assertpackable(::Packable) = true
+assertpackable(::Packable) = nothing
 assertpackable(t::Any) = throw(ArgumentError("Only simple objects can be shared with JS, like vectors and dictionaries. $(string(typeof(t))) is not compatible."))
-assertpackable(::Vector{<:Packable}) = true
-assertpackable(::Dict{<:Packable,<:Packable}) = true
+assertpackable(::Vector{<:Packable}) = nothing
+assertpackable(::Dict{<:Packable,<:Packable}) = nothing
 assertpackable(x::Vector) = foreach(assertpackable, x)
 assertpackable(d::Dict) = let
     foreach(assertpackable, keys(d))
@@ -2217,7 +2385,7 @@ function Base.show(io::IO, m::MIME"text/html", e::EmbeddableDisplay)
 
         // see https://plutocon2021-demos.netlify.app/fonsp%20%E2%80%94%20javascript%20inside%20pluto to learn about the techniques used in this script
         
-        const body = $(publish_to_js(body, e.script_id));
+        const body = $(PublishedToJavascript(body));
         const mime = "$(string(mime))";
         
         const create_new = this == null || this._mime !== mime;
@@ -2387,18 +2555,32 @@ function Logging.handle_message(pl::PlutoCellLogger, level, msg, _module, group,
     end
 
     try
-
         yield()
 
+        po() = get(cell_published_objects, pl.cell_id, Dict{String,Any}())
+        before_published_object_keys = collect(keys(po()))
+
+        # Render the log arguments:
+        msg_formatted = format_output_default(msg isa AbstractString ? Text(msg) : msg)
+        kwargs_formatted = Tuple{String,Any}[(string(k), format_log_value(v)) for (k, v) in kwargs if k != :maxlog]
+
+        after_published_object_keys = collect(keys(po()))
+        new_published_object_keys = setdiff(after_published_object_keys, before_published_object_keys)
+
+        # (Running `put!(pl.log_channel, x)` will send `x` to the pluto server. See `start_relaying_logs` for the receiving end.)
         put!(pl.log_channel, Dict{String,Any}(
             "level" => string(level),
-            "msg" => format_output_default(msg isa AbstractString ? Text(msg) : msg),
+            "msg" => msg_formatted,
+            # This is a dictionary containing all published objects that were published during the rendering of the log arguments (we cannot track which objects were published during the execution of the log statement itself i think...)
+            "new_published_objects" => Dict{String,Any}(
+                key => po()[key] for key in new_published_object_keys
+            ),
             "group" => string(group),
             "id" => string(id),
             "file" => string(file),
             "cell_id" => pl.cell_id,
             "line" => line isa Union{Int32,Int64} ? line : nothing,
-            "kwargs" => Tuple{String,Any}[(string(k), format_log_value(v)) for (k, v) in kwargs if k != :maxlog],
+            "kwargs" => kwargs_formatted,
         ))
 
         yield()
@@ -2463,6 +2645,9 @@ function with_io_to_logs(f::Function; enabled::Bool=true, loglevel::Logging.LogL
             _send_stdio_output!(output, loglevel)
         catch err
             @error "Failed to redirect stdout/stderr to logs"  exception=(err,catch_backtrace())
+            if err isa InterruptException
+                rethrow(err)
+            end
         end
     end
 
diff --git a/src/webserver/Authentication.jl b/src/webserver/Authentication.jl
index f74b4b7d68..45644703d5 100644
--- a/src/webserver/Authentication.jl
+++ b/src/webserver/Authentication.jl
@@ -103,8 +103,7 @@ function auth_middleware(handler)
                 filter!(p -> p[1] != "Access-Control-Allow-Origin", response.headers)
                 HTTP.setheader(response, "Access-Control-Allow-Origin" => "*")
             end
-            
-            if HTTP.URI(request.target).path ∈ ("", "/")
+            if required || HTTP.URI(request.target).path ∈ ("", "/")
                 add_set_secret_cookie!(session, response)
             end
             response
diff --git a/src/webserver/Dynamic.jl b/src/webserver/Dynamic.jl
index ba58104c4e..3a48c0e130 100644
--- a/src/webserver/Dynamic.jl
+++ b/src/webserver/Dynamic.jl
@@ -134,7 +134,7 @@ function notebook_to_js(notebook::Notebook)
                 "cell_id" => cell.cell_id,
                 "depends_on_disabled_cells" => cell.depends_on_disabled_cells,
                 "output" => FirebaseyUtils.ImmutableMarker(cell.output),
-                "published_object_keys" => keys(cell.published_objects),
+                "published_object_keys" => collect(keys(cell.published_objects)),
                 "queued" => cell.queued,
                 "running" => cell.running,
                 "errored" => cell.errored,
@@ -189,7 +189,7 @@ function send_notebook_changes!(🙋::ClientRequest; commentary::Any=nothing, sk
             if client.connected_notebook !== nothing && client.connected_notebook.notebook_id == 🙋.notebook.notebook_id
                 current_dict = get(current_state_for_clients, client, :empty)
                 patches = Firebasey.diff(current_dict, notebook_dict)
-                patches_as_dicts::Array{Dict} = Firebasey._convert(Array{Dict}, patches)
+                patches_as_dicts = Firebasey._convert(Vector{Dict}, patches)
                 current_state_for_clients[client] = deep_enough_copy(notebook_dict)
 
                 # Make sure we do send a confirmation to the client who made the request, even without changes
diff --git a/src/webserver/REPLTools.jl b/src/webserver/REPLTools.jl
index 74f432b19d..7da202f6ca 100644
--- a/src/webserver/REPLTools.jl
+++ b/src/webserver/REPLTools.jl
@@ -1,5 +1,5 @@
 import FuzzyCompletions: complete_path, completion_text, score
-import Distributed
+import Malt
 import .PkgCompat: package_completions
 using Markdown
 import REPL
@@ -83,10 +83,13 @@ responses[:complete] = function response_complete(🙋::ClientRequest)
         if will_run_code(🙋.notebook) && workspace isa WorkspaceManager.Workspace && isready(workspace.dowork_token)
             # we don't use eval_format_fetch_in_workspace because we don't want the output to be string-formatted.
             # This works in this particular case, because the return object, a `Completion`, exists in this scope too.
-            Distributed.remotecall_eval(Main, workspace.pid, :(PlutoRunner.completion_fetcher(
-                $query, $pos,
-                getfield(Main, $(QuoteNode(workspace.module_name))),
-                )))
+            Malt.remote_eval_fetch(workspace.worker, quote
+                PlutoRunner.completion_fetcher(
+                    $query,
+                    $pos,
+                    getfield(Main, $(QuoteNode(workspace.module_name))),
+                )
+            end)
         else
             # We can at least autocomplete general julia things:
             PlutoRunner.completion_fetcher(query, pos, Main)
@@ -132,10 +135,12 @@ responses[:docs] = function response_docs(🙋::ClientRequest)
         (repr(MIME("text/html"), doc_md), :👍)
     else
         if will_run_code(🙋.notebook) && workspace isa WorkspaceManager.Workspace && isready(workspace.dowork_token)
-            Distributed.remotecall_eval(Main, workspace.pid, :(PlutoRunner.doc_fetcher(
-                $query,
-                getfield(Main, $(QuoteNode(workspace.module_name))),
-            )))
+            Malt.remote_eval_fetch(workspace.worker, quote
+                PlutoRunner.doc_fetcher(
+                    $query,
+                    getfield(Main, $(QuoteNode(workspace.module_name))),
+                )
+            end)
         else
             (nothing, :⌛)
         end
diff --git a/src/webserver/WebServer.jl b/src/webserver/WebServer.jl
index fbdff63f5a..911a325704 100644
--- a/src/webserver/WebServer.jl
+++ b/src/webserver/WebServer.jl
@@ -23,8 +23,6 @@ function open_in_default_browser(url::AbstractString)::Bool
     end
 end
 
-isurl(s::String) = startswith(s, "http://") || startswith(s, "https://")
-
 function swallow_exception(f, exception_type::Type{T}) where {T}
     try
         f()
@@ -86,18 +84,6 @@ function run(port::Integer; kwargs...)
     "
 end
 
-# open notebook(s) on startup
-
-open_notebook!(session::ServerSession, notebook::Nothing) = Nothing
-
-open_notebook!(session::ServerSession, notebook::AbstractString) = SessionActions.open(session, notebook)
-
-function open_notebook!(session::ServerSession, notebook::AbstractVector{<:AbstractString})
-    for nb in notebook
-        SessionActions.open(session, nb)
-    end
-end
-
 
 const is_first_run = Ref(true)
 
@@ -117,12 +103,43 @@ function port_serversocket(hostIP::Sockets.IPAddr, favourite_port, port_hint)
     return port, serversocket
 end
 
+struct RunningPlutoServer
+    http_server
+    initial_registry_update_task::Task
+end
+
+function Base.close(ssc::RunningPlutoServer)
+    close(ssc.http_server)
+    wait(ssc.http_server)
+    wait(ssc.initial_registry_update_task)
+end
+
+function Base.wait(ssc::RunningPlutoServer)
+    try
+        # create blocking call and switch the scheduler back to the server task, so that interrupts land there
+        while isopen(ssc.http_server)
+            sleep(.1)
+        end
+    catch e
+        println()
+        println()
+        Base.close(ssc)
+        (e isa InterruptException) || rethrow(e)
+    end
+    
+    nothing
+end
+
 """
     run(session::ServerSession)
 
 Specifiy the [`Pluto.ServerSession`](@ref) to run the web server on, which includes the configuration. Passing a session as argument allows you to start the web server with some notebooks already running. See [`SessionActions`](@ref) to learn more about manipulating a `ServerSession`.
 """
 function run(session::ServerSession)
+    Base.wait(run!(session))
+end
+
+function run!(session::ServerSession)
     if is_first_run[]
         is_first_run[] = false
         @info "Loading..."
@@ -136,8 +153,14 @@ function run(session::ServerSession)
     store_session_middleware = create_session_context_middleware(session)
     app = pluto_router |> auth_middleware |> store_session_middleware
 
-    notebook_at_startup = session.options.server.notebook
-    open_notebook!(session, notebook_at_startup)
+    let n = session.options.server.notebook
+        SessionActions.open.((session,), 
+            n === nothing ? [] : 
+            n isa AbstractString ? [n] : 
+            n;
+            run_async=true,
+        )
+    end
 
     host = session.options.server.host
     hostIP = parse(Sockets.IPAddr, host)
@@ -301,28 +324,10 @@ function run(session::ServerSession)
         will_update && println("    Updating registry done ✓")
     end
 
-    try
-        # create blocking call and switch the scheduler back to the server task, so that interrupts land there
-        while isopen(server)
-            sleep(.1)
-        end
-    catch e
-        println()
-        println()
-        close(server)
-        wait(server)
-        wait(initial_registry_update_task)
-        (e isa InterruptException) || rethrow(e)
-    end
-    
-    nothing
+    return RunningPlutoServer(server, initial_registry_update_task)
 end
 precompile(run, (ServerSession, HTTP.Handlers.Router{Symbol("##001")}))
 
-get_favorite_notebook(notebook::Nothing) = nothing
-get_favorite_notebook(notebook::String) = notebook
-get_favorite_notebook(notebook::AbstractVector) = first(notebook)
-
 function pretty_address(session::ServerSession, hostIP, port)
     root = if session.options.server.root_url !== nothing
         @assert endswith(session.options.server.root_url, "/")
@@ -352,10 +357,12 @@ function pretty_address(session::ServerSession, hostIP, port)
     if session.options.security.require_secret_for_access
         url_params["secret"] = session.secret
     end
-    fav_notebook = get_favorite_notebook(session.options.server.notebook)
+    fav_notebook = let n = session.options.server.notebook
+        n isa AbstractVector ? (isempty(n) ? nothing : first(n)) : n
+    end
     new_root = if fav_notebook !== nothing
-        key = isurl(fav_notebook) ? "url" : "path"
-        url_params[key] = string(fav_notebook)
+        # since this notebook already started running, this will get redicted to that session
+        url_params["path"] = string(fav_notebook)
         root * "open"
     else
         root
diff --git a/test/Bonds.jl b/test/Bonds.jl
index 3fe9e559c4..bf1b028e09 100644
--- a/test/Bonds.jl
+++ b/test/Bonds.jl
@@ -1,7 +1,7 @@
 using Test
 import Pluto
 import Pluto: update_run!, update_save_run!, WorkspaceManager, ClientSession, ServerSession, Notebook, Cell
-import Distributed
+import Malt
 
 @testset "Bonds" begin
 
@@ -358,9 +358,8 @@ import Distributed
         
         # test that the notebook file is runnable:
         
-        test_proc = Distributed.addprocs(1)[1]
-        
-        Distributed.remotecall_eval(Main, test_proc, quote
+        test_proc = Malt.Worker()
+        Malt.remote_eval_wait(test_proc, quote
             import Pkg
             try
                 Pkg.UPDATED_REGISTRY_THIS_SESSION[] = true
@@ -368,11 +367,11 @@ import Distributed
             Pkg.activate(mktempdir())
             Pkg.add("AbstractPlutoDingetjes")
         end)
-        @test Distributed.remotecall_eval(Main, test_proc, quote
+        @test Malt.remote_eval_fetch(test_proc, quote
             include($(notebook.path))
             true
         end)
-        Distributed.rmprocs(test_proc)
+        Malt.stop(test_proc)
     end
 
     @testset "Dependent Bound Variables" begin
diff --git a/test/Configuration.jl b/test/Configuration.jl
index 0b6b131618..4d2d6c2f54 100644
--- a/test/Configuration.jl
+++ b/test/Configuration.jl
@@ -64,8 +64,7 @@ end
     host = 🍭.options.server.host
     secret = 🍭.secret
     println("Launching test server...")
-    server_task = @async Pluto.run(🍭)
-    sleep(2)
+    server = Pluto.run!(🍭)
 
     local_url(suffix) = "http://$host:$port/$suffix"
     withsecret(url) = occursin('?', url) ? "$url&secret=$secret" : "$url?secret=$secret"
@@ -123,43 +122,7 @@ end
         @test requeststatus(url, method) ∈ 200:399 # 3xx are redirects
     end
 
-    @async schedule(server_task, InterruptException(); error=true)
-end
-
-@testset "Open Notebooks at Startup" begin
-    port = 1338
-    host = "localhost"
-    local_url(suffix) = "http://$host:$port/$suffix"
-
-    urls = [
-    "https://raw.githubusercontent.com/fonsp/Pluto.jl/v0.12.16/sample/Basic.jl",
-    "https://gist.githubusercontent.com/fonsp/4e164a262a60fc4bdd638e124e629d64/raw/8ffe93c680e539056068456a62dea7bf6b8eb622/basic_pkg_notebook.jl",
-    ]
-    nbnames = download.(urls)
-    
-    server_running() = HTTP.get(local_url("favicon.ico")).status == 200 && HTTP.get(local_url("edit")).status == 200
-
-    # without notebook at startup
-    server_task = @async Pluto.run(port=port, launch_browser=false, workspace_use_distributed=false, require_secret_for_access=false, require_secret_for_open_links=false)
-    @test poll(5) do
-        server_running()
-    end
-    @async schedule(server_task, InterruptException(); error=true)
-
-    # with a single notebook at startup
-    server_task = @async Pluto.run(notebook=first(nbnames), port=port, launch_browser=false, workspace_use_distributed=false, require_secret_for_access=false, require_secret_for_open_links=false)
-    @test poll(5) do
-        server_running()
-    end
-    @async schedule(server_task, InterruptException(); error=true)
-
-    # with multiple notebooks at startup
-    server_task = @async Pluto.run(notebook=nbnames, port=port, launch_browser=false, workspace_use_distributed=false, require_secret_for_access=false, require_secret_for_open_links=false)
-    @test poll(5) do
-        server_running()
-    end
-    @async schedule(server_task, InterruptException(); error=true)
-
+    close(server)
 end
 
 @testset "disable mimetype via workspace_custom_startup_expr" begin
@@ -183,7 +146,4 @@ end
     Pluto.WorkspaceManager.unmake_workspace((🍭, nb))
 end
 
-# TODO are the processes closed properly?
-# TODO we reuse the same port without awaiting the shutdown of the previous server
-
-end # testset
+end
diff --git a/test/Dynamic.jl b/test/Dynamic.jl
index ed0e3e12c8..1d8675c740 100644
--- a/test/Dynamic.jl
+++ b/test/Dynamic.jl
@@ -156,7 +156,7 @@ end
         let
             doc_output = Pluto.PlutoRunner.doc_fetcher("sor", Main)[1]
             @test occursin("Similar results:", doc_output)
-            @test occursin("<b>s</b><b>o</b><b>r</b>tperm", doc_output)
+            @test occursin("<b>s</b><b>o</b><b>r</b>t", doc_output)
         end
 
         @test occursin("\\div", Pluto.PlutoRunner.doc_fetcher("÷", Main)[1])
@@ -193,24 +193,51 @@ end
 
     @testset "PlutoRunner API" begin
         🍭 = ServerSession()
-        🍭.options.evaluation.workspace_use_distributed = true
+        # 🍭.options.evaluation.workspace_use_distributed = true
+        
+        cid = uuid1()
 
         notebook = Notebook([
             Cell("PlutoRunner.notebook_id[] |> Text"),
-            Cell("""
-            let
-                # not actually public API but we test it anyways
-                a = PlutoRunner._publish(Dict(
+            # These cells tests `core_published_to_js`, which is the function used by the official API (`AbtractPlutoDingetjes.Display.published_to_js`).
+            Cell(cid, """
+            begin
+                
+                a = Dict(
                     "hello" => "world",
                     "xx" => UInt8[6,7,8],
-                ))
-                b = PlutoRunner._publish("cool")
-                Text((a, b))
+                )
+                b = "cool"
+                
+                struct ZZZ
+                    x
+                    y
+                end
+                
+                function Base.show(io::IO, ::MIME"text/html", z::ZZZ)
+                    write(io, "<script>\n")
+                    PlutoRunner.core_published_to_js(io, z.x)
+                    PlutoRunner.core_published_to_js(io, z.y)
+                    write(io, "\n</script>")
+                end
+                
+                ZZZ(a, b)
+            end
+            """),
+            Cell("""
+            begin
+                struct ABC
+                    x
+                end
+                ZZZ(
+                    123, 
+                    Dict("a" => 234, "b" => ABC(4)),
+                )
             end
             """),
-            Cell("3"),
+            # This is the deprecated API:
             Cell("PlutoRunner.publish_to_js(Ref(4))"),
-            Cell("PlutoRunner.publish_to_js((ref=4,))"),
+            Cell("PlutoRunner.publish_to_js((ref=5,))"),
             Cell("x = Dict(:a => 6)"),
             Cell("PlutoRunner.publish_to_js(x)"),
         ])
@@ -218,11 +245,17 @@ end
         update_save_run!(🍭, notebook, notebook.cells)
         @test notebook.cells[1].output.body == notebook.notebook_id |> string
 
-        @test !notebook.cells[2].errored
-        a, b = Meta.parse(notebook.cells[2].output.body) |> eval
+        @test notebook.cells[2] |> noerror
+        @test notebook.cells[2].output.mime isa MIME"text/html"
+
+        ab1, ab2 = keys(notebook.cells[2].published_objects)
+        @test occursin(ab1, notebook.cells[2].output.body)
+        @test occursin(ab2, notebook.cells[2].output.body)
+        
+        ab() = sort(collect(keys(notebook.cells[2].published_objects)); by=(s -> findfirst(s, notebook.cells[2].output.body) |> first))
+        a, b = ab()
+        
         p = notebook.cells[2].published_objects
-        @test sort(collect(keys(p))) == sort([a,b])
-        @test isempty(notebook.cells[3].published_objects)
 
         @test p[a] == Dict(
             "hello" => "world",
@@ -234,18 +267,29 @@ end
         old_pb = p[b]
         update_save_run!(🍭, notebook, notebook.cells)
         p = notebook.cells[2].published_objects
-        a, b = Meta.parse(notebook.cells[2].output.body) |> eval
+        a, b = ab()
         @test p[a] == old_pa
         @test p[b] == old_pb
         
         @test !isempty(notebook.cells[2].published_objects)
         
+        # display should have failed
+        @test only(values(notebook.cells[3].published_objects)) == 123
+        msg = notebook.cells[3].output.body[:msg]
+        @test occursin("Failed to show value", msg)
+        @test occursin("ABC is not compatible", msg)
+        
+        
+        
         setcode!(notebook.cells[2], "2")
         update_save_run!(🍭, notebook, notebook.cells)
         @test isempty(notebook.cells[2].published_objects)
-
+        @test isempty(notebook.cells[2].published_objects)
+        
+        
+        
         @test notebook.cells[4].errored
-        @test !notebook.cells[5].errored
+        @test notebook.cells[5] |> noerror
         @test !isempty(notebook.cells[5].published_objects)
         
         
diff --git a/test/ExpressionExplorer.jl b/test/ExpressionExplorer.jl
index 505b7470ea..5ab13b83a9 100644
--- a/test/ExpressionExplorer.jl
+++ b/test/ExpressionExplorer.jl
@@ -1,4 +1,5 @@
 using Test
+import Pluto: PlutoRunner
 
 #=
 `@test_broken` means that the test doesn't pass right now, but we want it to pass. Feel free to try to fix it and open a PR!
@@ -165,6 +166,9 @@ Some of these @test_broken lines are commented out to prevent printing to the te
         @test testee(:(x = let a = 1; a += b end), [:b], [:x], [:+], [])
         @test testee(:(_ = a + 1), [:a], [], [:+], [])
         @test testee(:(a = _ + 1), [], [:a], [:+], [])
+
+        @test testee(:(f()[] = 1), [], [], [:f], [])
+        @test testee(:(x[f()] = 1), [:x], [], [:f], [])
     end
     @testset "Multiple assignments" begin
         # Note that using the shorthand syntax :(a = 1, b = 2) to create an expression
@@ -206,6 +210,18 @@ Some of these @test_broken lines are commented out to prevent printing to the te
         @test testee(quote
             a, b... = 0:5
         end, [],[:a, :b], [[:(:)]], [])
+        @test testee(quote
+            a[x], x = 1, 2
+        end, [:a], [:x], [], [])
+        @test testee(quote
+            x, a[x] = 1, 2
+        end, [:a], [:x], [], [])
+        @test testee(quote
+            f, a[f()] = g
+        end, [:g, :a], [:f], [], [])
+        @test testee(quote
+            a[f()], f = g
+        end, [:g, :a], [:f], [], [])
         @test testee(quote (; a, b) = x end, [:x], [:a, :b], [], [])
         @test testee(quote a = (b, c) end, [:b, :c], [:a], [], [])
 
@@ -780,3 +796,16 @@ Some of these @test_broken lines are commented out to prevent printing to the te
         @test :Date ∈ rn.references
     end
 end
+
+@testset "UTF-8 to Codemirror UTF-16 byte mapping" begin
+    # range ends are non inclusives
+    tests = [
+        (" aaaa", (2, 4), (1, 3)), # cm is zero based
+        (" 🍕🍕", (2, 6), (1, 3)), # a 🍕 is two UTF16 codeunits
+        (" 🍕🍕", (6, 10), (3, 5)), # a 🍕 is two UTF16 codeunits
+    ]
+    for (s, (start_byte, end_byte), (from, to)) in tests
+        @show s
+        @test PlutoRunner.map_byte_range_to_utf16_codepoints(s, start_byte, end_byte) == (from, to)
+    end
+end
diff --git a/test/MacroAnalysis.jl b/test/MacroAnalysis.jl
index 171f9e8ce0..4c54571674 100644
--- a/test/MacroAnalysis.jl
+++ b/test/MacroAnalysis.jl
@@ -624,7 +624,7 @@ import Memoize: @memoize
 
     @testset "Package macro 2" begin
         🍭.options.evaluation.workspace_use_distributed = true
-        
+
         notebook = Notebook([
             Cell("z = x^2 + y"),
             Cell("@variables x y"),
@@ -632,7 +632,7 @@ import Memoize: @memoize
             begin
                 import Pkg
                 Pkg.activate(mktempdir())
-                Pkg.add(Pkg.PackageSpec(name="Symbolics", version="1"))
+                Pkg.add(Pkg.PackageSpec(name="Symbolics", version="5.5.1"))
                 import Symbolics: @variables
             end
             """),
@@ -648,7 +648,7 @@ import Memoize: @memoize
 
         @test cell(1) |> noerror
         @test cell(2) |> noerror
-        @test cell(2) |> noerror
+        @test cell(3) |> noerror
 
         update_run!(🍭, notebook, notebook.cells)
 
diff --git a/test/React.jl b/test/React.jl
index 191540c53a..bb249032c9 100644
--- a/test/React.jl
+++ b/test/React.jl
@@ -1,14 +1,15 @@
 using Test
 import Pluto: Configuration, Notebook, ServerSession, ClientSession, update_run!, Cell, WorkspaceManager
 import Pluto.Configuration: Options, EvaluationOptions
-import Distributed
 
 @testset "Reactivity" begin
     🍭 = ServerSession()
     🍭.options.evaluation.workspace_use_distributed = false
 
-    @testset "Basic $(parallel ? "distributed" : "single-process")" for parallel in [false, true]
-        🍭.options.evaluation.workspace_use_distributed = parallel
+    @testset "Basic $workertype" for workertype in [:Malt, :Distributed, :InProcess]
+        🍭.options.evaluation.workspace_use_distributed = workertype !== :InProcess
+        🍭.options.evaluation.workspace_use_distributed_stdlib = workertype === :Distributed
+        
         
         notebook = Notebook([
             Cell("x = 1"),
@@ -22,7 +23,13 @@ import Distributed
             end"""),
             Cell("g(6) + g(6,6)"),
 
-            Cell("import Distributed"),
+            Cell("""
+            begin
+                pushfirst!(LOAD_PATH, "@stdlib")
+                import Distributed
+                popfirst!(LOAD_PATH)
+            end
+            """),
             Cell("Distributed.myid()"),
         ])
 
@@ -70,10 +77,14 @@ import Distributed
         @test notebook.cells[6].output.body == "3"
 
         update_run!(🍭, notebook, notebook.cells[7:8])
-        @test if parallel
-            notebook.cells[8].output.body != string(Distributed.myid())
+        if workertype === :Distributed
+            @test notebook.cells[8].output.body ∉ ("1", string(Distributed.myid()))
+        elseif workertype === :Malt
+            @test notebook.cells[8].output.body == "1"
+        elseif workertype === :InProcess
+            @test notebook.cells[8].output.body == string(Distributed.myid())
         else
-            notebook.cells[8].output.body == string(Distributed.myid())
+            error()
         end
 
         WorkspaceManager.unmake_workspace((🍭, notebook); verbose=false)
@@ -1752,4 +1763,28 @@ import Distributed
         update_run!(🍭, notebook, notebook.cells)
         @test all(noerror, notebook.cells)
     end
+
+    @testset "ParseError messages" begin
+        notebook = Notebook(Cell.([
+            "begin",
+            "\n\nend",
+        ]))
+        update_run!(🍭, notebook, notebook.cells)
+        @test Pluto.is_just_text(notebook.topology, notebook.cells[1])
+        @test Pluto.is_just_text(notebook.topology, notebook.cells[2])
+        @static if VERSION >= v"1.10.0-DEV.1548" # ~JuliaSyntax PR Pluto.jl#2526 julia#46372
+            @test haskey(notebook.cells[1].output.body, :source)
+            @test haskey(notebook.cells[1].output.body, :diagnostics)
+
+            @test haskey(notebook.cells[2].output.body, :source)
+            @test haskey(notebook.cells[2].output.body, :diagnostics)
+        else
+            @test !occursinerror("(incomplete ", notebook.cells[1])
+            @test !occursinerror("(incomplete ", notebook.cells[2])
+
+            @show notebook.cells[1].output.body
+            @test startswith(notebook.cells[1].output.body[:msg], "syntax:")
+            @test startswith(notebook.cells[2].output.body[:msg], "syntax:")
+        end
+    end
 end
diff --git a/test/ReloadFromFile.jl b/test/ReloadFromFile.jl
index 01bf9358ca..ec602fee3c 100644
--- a/test/ReloadFromFile.jl
+++ b/test/ReloadFromFile.jl
@@ -1,7 +1,6 @@
 using Test
 import Pluto: Configuration, Notebook, ServerSession, ClientSession, update_run!, Cell, WorkspaceManager, SessionActions, save_notebook
 import Pluto.Configuration: Options, EvaluationOptions
-import Distributed
 using Pluto.WorkspaceManager: poll
 import Pkg
 
@@ -101,14 +100,14 @@ end
     sleep(timeout_between_tests)
     
     file4 = read(notebook.path, String)
+    last_hot_reload_time4 = notebook.last_hot_reload_time
     notebook.cells[3].code_folded = true
     save_notebook(notebook)
     sleep(timeout_between_tests)
     
     file5 = read(notebook.path, String)
-    @assert file4 != file5
-    
-    @assert notebook.cells[3].code_folded
+    @test file4 != file5
+    @test notebook.cells[3].code_folded
     write(notebook.path, file4)
     
     
@@ -119,7 +118,10 @@ end
     # cell folded, but cell should not re-run
     @assert original_rand_output == notebook.cells[3].output.body
 
-    
+    @assert poll(10) do
+        last_hot_reload_time5 = notebook.last_hot_reload_time
+        last_hot_reload_time5 != last_hot_reload_time4
+    end
         
     ###
     sleep(timeout_between_tests)
@@ -160,4 +162,4 @@ end
     @assert notebook.nbpkg_restart_required_msg !== nothing
 end
 @test true
-end
\ No newline at end of file
+end
diff --git a/test/RichOutput.jl b/test/RichOutput.jl
index 1132472112..69e1eccff9 100644
--- a/test/RichOutput.jl
+++ b/test/RichOutput.jl
@@ -229,6 +229,21 @@ import Pluto: update_run!, WorkspaceManager, ClientSession, ServerSession, Noteb
         end
     end
 
+    @testset "embed_display" begin
+        🍭.options.evaluation.workspace_use_distributed = false
+        notebook = Notebook([
+            Cell("x = randn(10)"),
+            Cell(raw"md\"x = $(embed_display(x))\"")
+        ])
+        update_run!(🍭, notebook, notebook.cells)
+
+        @test notebook.cells[1] |> noerror
+        @test notebook.cells[2] |> noerror
+
+        @test notebook.cells[2].output.body isa String
+        @test occursin("getPublishedObject", notebook.cells[2].output.body)
+    end
+
     @testset "Table viewer" begin
         🍭.options.evaluation.workspace_use_distributed = true
         notebook = Notebook([
diff --git a/test/WorkspaceManager.jl b/test/WorkspaceManager.jl
index 92975be90a..fc7138e4a9 100644
--- a/test/WorkspaceManager.jl
+++ b/test/WorkspaceManager.jl
@@ -2,7 +2,7 @@ using Test
 using Pluto.Configuration: CompilerOptions
 using Pluto.WorkspaceManager: _merge_notebook_compiler_options
 import Pluto: update_save_run!, update_run!, WorkspaceManager, ClientSession, ServerSession, Notebook, Cell, project_relative_path
-import Distributed
+import Malt
 
 @testset "Workspace manager" begin
 # basic functionality is already tested by the reactivity tests
@@ -54,7 +54,8 @@ import Distributed
 
     Sys.iswindows() || @testset "Pluto inside Pluto" begin
         🍭 = ServerSession()
-        🍭.options.evaluation.workspace_use_distributed = true
+        🍭.options.evaluation.capture_stdout = false
+        🍭.options.evaluation.workspace_use_distributed_stdlib = false
 
         notebook = Notebook([
             Cell("""begin
@@ -65,7 +66,10 @@ import Distributed
                 import Pluto
             end"""),
             Cell("""
-            s = Pluto.ServerSession()
+            begin
+                s = Pluto.ServerSession()
+                s.options.evaluation.workspace_use_distributed_stdlib = false
+            end
             """),
             Cell("""
             nb = Pluto.SessionActions.open(s, Pluto.project_relative_path("sample", "Tower of Hanoi.jl"); run_async=false, as_sample=true)
@@ -86,17 +90,10 @@ import Distributed
         update_run!(🍭, notebook, notebook.cells[5])
         @test notebook.cells[5] |> noerror
 
-
-        desired_nprocs = Distributed.nprocs() - 1
         setcode!(notebook.cells[5], "Pluto.SessionActions.shutdown(s, nb)")
         update_run!(🍭, notebook, notebook.cells[5])
         @test noerror(notebook.cells[5])
 
-        while Distributed.nprocs() != desired_nprocs
-            sleep(.1)
-        end
-        sleep(.1)
-
         WorkspaceManager.unmake_workspace((🍭, notebook))
     end
 end
diff --git a/test/cell_disabling.jl b/test/cell_disabling.jl
index f5f9575dd3..3c8e8f498b 100644
--- a/test/cell_disabling.jl
+++ b/test/cell_disabling.jl
@@ -1,6 +1,6 @@
 using Test
 using Pluto
-using Pluto: update_run!, ServerSession, ClientSession, Cell, Notebook, set_disabled, is_disabled
+using Pluto: update_run!, ServerSession, ClientSession, Cell, Notebook, set_disabled, is_disabled, WorkspaceManager
 
 
 
@@ -236,6 +236,7 @@ using Pluto: update_run!, ServerSession, ClientSession, Cell, Notebook, set_disa
     update_run!(🍭, notebook, c([12]))
     @test c(14).output.body == "3"
     
+    WorkspaceManager.unmake_workspace((🍭, notebook))
 end
 
 
@@ -342,4 +343,5 @@ end
     update_run!(🍭, notebook, notebook.cells)
     @test get_disabled_cells(notebook) == []
 
+    WorkspaceManager.unmake_workspace((🍭, notebook))
 end
diff --git a/test/frontend/__tests__/published_to_js.js b/test/frontend/__tests__/published_to_js.js
new file mode 100644
index 0000000000..348b3cd6bf
--- /dev/null
+++ b/test/frontend/__tests__/published_to_js.js
@@ -0,0 +1,58 @@
+import puppeteer from "puppeteer"
+import { lastElement, saveScreenshot, getTestScreenshotPath, createPage } from "../helpers/common"
+import {
+    getCellIds,
+    importNotebook,
+    waitForCellOutput,
+    getPlutoUrl,
+    prewarmPluto,
+    writeSingleLineInPlutoInput,
+    waitForNoUpdateOngoing,
+    shutdownCurrentNotebook,
+    setupPlutoBrowser,
+} from "../helpers/pluto"
+
+describe("published_to_js", () => {
+    /**
+     * Launch a shared browser instance for all tests.
+     * I don't use jest-puppeteer because it takes away a lot of control and works buggy for me,
+     * so I need to manually create the shared browser.
+     * @type {puppeteer.Browser}
+     */
+    let browser = null
+    /** @type {puppeteer.Page} */
+    let page = null
+    beforeAll(async () => {
+        browser = await setupPlutoBrowser()
+    })
+    beforeEach(async () => {
+        page = await createPage(browser)
+        await page.goto(getPlutoUrl(), { waitUntil: "networkidle0" })
+    })
+    afterEach(async () => {
+        await saveScreenshot(page)
+        await shutdownCurrentNotebook(page)
+        await page.close()
+        page = null
+    })
+    afterAll(async () => {
+        await browser.close()
+        browser = null
+    })
+
+    it("Should correctly show published_to_js in cell output, and in logs", async () => {
+        await importNotebook(page, "published_to_js.jl")
+        await waitForNoUpdateOngoing(page, { polling: 100 })
+        let output_of_published = await page.evaluate(() => {
+            return document.querySelector("#to_cell_output")?.textContent
+        })
+        expect(output_of_published).toBe("[1,2,3] MAGIC!")
+
+        // The log content is not shown, so #to_cell_log does not exist
+        let log_of_published = await page.evaluate(() => {
+            return document.querySelector("#to_cell_log")?.textContent
+        })
+        // This test is currently broken, due to https://github.com/fonsp/Pluto.jl/issues/2092
+        // expect(log_of_published).toBe("[4,5,6] MAGIC!")
+    })
+})
diff --git a/test/frontend/fixtures/published_to_js.jl b/test/frontend/fixtures/published_to_js.jl
new file mode 100644
index 0000000000..1e8356e57c
--- /dev/null
+++ b/test/frontend/fixtures/published_to_js.jl
@@ -0,0 +1,50 @@
+### A Pluto.jl notebook ###
+# v0.19.27
+
+using Markdown
+using InteractiveUtils
+
+# ╔═╡ 2d69377e-23f8-11ee-116b-fb6a8f328528
+begin
+	using Pkg
+	Pkg.activate(temp=true)
+	# the latest versions of these packages:
+	Pkg.add(url="https://github.com/JuliaPluto/AbstractPlutoDingetjes.jl", rev="main")
+	Pkg.add("HypertextLiteral")
+end
+
+# ╔═╡ 2ea26a4b-2d1e-4bcb-8b7b-cace79f7926a
+begin
+	using AbstractPlutoDingetjes.Display: published_to_js
+	using HypertextLiteral
+end
+
+# ╔═╡ 043829fc-af3a-40b9-bb4f-f848ab50eb25
+a = [1,2,3];
+
+# ╔═╡ 2f4609fd-7361-4048-985a-2cc74bb25606
+@htl """
+<script>
+const a = JSON.stringify($(published_to_js(a))) + " MAGIC!"
+return html`<div id='to_cell_output'>\${a}</div>`
+</script>
+"""
+
+# ╔═╡ 28eba9fd-0416-49b8-966e-03a381c19ca7
+b = [4,5,6];
+
+# ╔═╡ 0a4e8a19-6d43-4161-bb8c-1ebf8f8f68ba
+@info @htl """
+<script>
+const a = JSON.stringify($(published_to_js(b))) + " MAGIC!"
+return html`<div id='to_cell_log'>\${a}</div>`
+</script>
+"""
+
+# ╔═╡ Cell order:
+# ╠═2d69377e-23f8-11ee-116b-fb6a8f328528
+# ╠═2ea26a4b-2d1e-4bcb-8b7b-cace79f7926a
+# ╠═043829fc-af3a-40b9-bb4f-f848ab50eb25
+# ╠═2f4609fd-7361-4048-985a-2cc74bb25606
+# ╠═28eba9fd-0416-49b8-966e-03a381c19ca7
+# ╠═0a4e8a19-6d43-4161-bb8c-1ebf8f8f68ba
diff --git a/test/frontend/helpers/common.js b/test/frontend/helpers/common.js
index 49f894c06f..572d03e33b 100644
--- a/test/frontend/helpers/common.js
+++ b/test/frontend/helpers/common.js
@@ -198,7 +198,7 @@ export const createPage = async (browser) => {
     page.on("request", (request) => {
       if(blocked_domains.some(domain => request.url().includes(domain))) {
         if(!hide_warning(request.url()))
-          console.error(`Blocking request to ${request.url()}`)
+          console.info(`Blocking request to ${request.url()}`)
         request.abort();
       } else {
         request.continue();
diff --git a/test/frontend/package-lock.json b/test/frontend/package-lock.json
index df0fc81029..9f056296f2 100644
--- a/test/frontend/package-lock.json
+++ b/test/frontend/package-lock.json
@@ -7320,6 +7320,12 @@
         }
       }
     },
+    "node_modules/querystringify": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/querystringify/-/querystringify-2.2.0.tgz",
+      "integrity": "sha512-FIqgj2EUvTa7R50u0rGsyTftzjYmv/a3hO345bZNrqabNqjtgiDMgmo4mkUjd+nzU5oF3dClKqFIPUKybUyqoQ==",
+      "dev": true
+    },
     "node_modules/react-is": {
       "version": "17.0.2",
       "resolved": "https://registry.npmjs.org/react-is/-/react-is-17.0.2.tgz",
@@ -7519,6 +7525,12 @@
       "integrity": "sha512-NKN5kMDylKuldxYLSUfrbo5Tuzh4hd+2E8NPPX02mZtn1VuREQToYe/ZdlJy+J3uCpfaiGF05e7B8W0iXbQHmg==",
       "dev": true
     },
+    "node_modules/requires-port": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/requires-port/-/requires-port-1.0.0.tgz",
+      "integrity": "sha512-KigOCHcocU3XODJxsu8i/j8T9tzT4adHiecwORRQ0ZZFcp7ahwXuRU1m+yuO90C5ZUyGeGfocHDI14M3L3yDAQ==",
+      "dev": true
+    },
     "node_modules/resolve": {
       "version": "1.22.0",
       "resolved": "https://registry.npmjs.org/resolve/-/resolve-1.22.0.tgz",
@@ -8724,14 +8736,15 @@
       }
     },
     "node_modules/tough-cookie": {
-      "version": "4.0.0",
-      "resolved": "https://registry.npmjs.org/tough-cookie/-/tough-cookie-4.0.0.tgz",
-      "integrity": "sha512-tHdtEpQCMrc1YLrMaqXXcj6AxhYi/xgit6mZu1+EDWUn+qhUf8wMQoFIy9NXuq23zAwtcB0t/MjACGR18pcRbg==",
+      "version": "4.1.3",
+      "resolved": "https://registry.npmjs.org/tough-cookie/-/tough-cookie-4.1.3.tgz",
+      "integrity": "sha512-aX/y5pVRkfRnfmuX+OdbSdXvPe6ieKX/G2s7e98f4poJHnqH3281gDPm/metm6E/WRamfx7WC4HUqkWHfQHprw==",
       "dev": true,
       "dependencies": {
         "psl": "^1.1.33",
         "punycode": "^2.1.1",
-        "universalify": "^0.1.2"
+        "universalify": "^0.2.0",
+        "url-parse": "^1.5.3"
       },
       "engines": {
         "node": ">=6"
@@ -8866,9 +8879,9 @@
       }
     },
     "node_modules/universalify": {
-      "version": "0.1.2",
-      "resolved": "https://registry.npmjs.org/universalify/-/universalify-0.1.2.tgz",
-      "integrity": "sha512-rBJeI5CXAlmy1pV+617WB9J63U6XcazHHF2f2dbJix4XzpUF0RS3Zbj0FGIOCAva5P/d/GBOYaACQ1w+0azUkg==",
+      "version": "0.2.0",
+      "resolved": "https://registry.npmjs.org/universalify/-/universalify-0.2.0.tgz",
+      "integrity": "sha512-CJ1QgKmNg3CwvAv/kOFmtnEN05f0D/cn9QntgNOQlQF9dgvVTHj3t+8JPdjqawCHk7V/KA+fbUqzZ9XWhcqPUg==",
       "dev": true,
       "engines": {
         "node": ">= 4.0.0"
@@ -8929,6 +8942,16 @@
       "deprecated": "Please see https://github.com/lydell/urix#deprecated",
       "dev": true
     },
+    "node_modules/url-parse": {
+      "version": "1.5.10",
+      "resolved": "https://registry.npmjs.org/url-parse/-/url-parse-1.5.10.tgz",
+      "integrity": "sha512-WypcfiRhfeUP9vvF0j6rw0J3hrWrw6iZv3+22h6iRMJ/8z1Tj6XfLP4DsUix5MhMPnXpiHDoKyoZ/bdCkwBCiQ==",
+      "dev": true,
+      "dependencies": {
+        "querystringify": "^2.1.1",
+        "requires-port": "^1.0.0"
+      }
+    },
     "node_modules/use": {
       "version": "3.1.1",
       "resolved": "https://registry.npmjs.org/use/-/use-3.1.1.tgz",
@@ -9077,9 +9100,9 @@
       "dev": true
     },
     "node_modules/word-wrap": {
-      "version": "1.2.3",
-      "resolved": "https://registry.npmjs.org/word-wrap/-/word-wrap-1.2.3.tgz",
-      "integrity": "sha512-Hz/mrNwitNRh/HUAtM/VT/5VH+ygD6DV7mYKZAtHOrbs8U7lvPS6xf7EJKMF0uW1KJCl0H701g3ZGus+muE5vQ==",
+      "version": "1.2.4",
+      "resolved": "https://registry.npmjs.org/word-wrap/-/word-wrap-1.2.4.tgz",
+      "integrity": "sha512-2V81OA4ugVo5pRo46hAoD2ivUJx8jXmWXfUkY4KFNw0hEptvN0QfH3K4nHiwzGeKl5rFKedV48QVoqYavy4YpA==",
       "dev": true,
       "engines": {
         "node": ">=0.10.0"
@@ -14716,6 +14739,12 @@
         }
       }
     },
+    "querystringify": {
+      "version": "2.2.0",
+      "resolved": "https://registry.npmjs.org/querystringify/-/querystringify-2.2.0.tgz",
+      "integrity": "sha512-FIqgj2EUvTa7R50u0rGsyTftzjYmv/a3hO345bZNrqabNqjtgiDMgmo4mkUjd+nzU5oF3dClKqFIPUKybUyqoQ==",
+      "dev": true
+    },
     "react-is": {
       "version": "17.0.2",
       "resolved": "https://registry.npmjs.org/react-is/-/react-is-17.0.2.tgz",
@@ -14879,6 +14908,12 @@
       "integrity": "sha512-NKN5kMDylKuldxYLSUfrbo5Tuzh4hd+2E8NPPX02mZtn1VuREQToYe/ZdlJy+J3uCpfaiGF05e7B8W0iXbQHmg==",
       "dev": true
     },
+    "requires-port": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/requires-port/-/requires-port-1.0.0.tgz",
+      "integrity": "sha512-KigOCHcocU3XODJxsu8i/j8T9tzT4adHiecwORRQ0ZZFcp7ahwXuRU1m+yuO90C5ZUyGeGfocHDI14M3L3yDAQ==",
+      "dev": true
+    },
     "resolve": {
       "version": "1.22.0",
       "resolved": "https://registry.npmjs.org/resolve/-/resolve-1.22.0.tgz",
@@ -15842,14 +15877,15 @@
       }
     },
     "tough-cookie": {
-      "version": "4.0.0",
-      "resolved": "https://registry.npmjs.org/tough-cookie/-/tough-cookie-4.0.0.tgz",
-      "integrity": "sha512-tHdtEpQCMrc1YLrMaqXXcj6AxhYi/xgit6mZu1+EDWUn+qhUf8wMQoFIy9NXuq23zAwtcB0t/MjACGR18pcRbg==",
+      "version": "4.1.3",
+      "resolved": "https://registry.npmjs.org/tough-cookie/-/tough-cookie-4.1.3.tgz",
+      "integrity": "sha512-aX/y5pVRkfRnfmuX+OdbSdXvPe6ieKX/G2s7e98f4poJHnqH3281gDPm/metm6E/WRamfx7WC4HUqkWHfQHprw==",
       "dev": true,
       "requires": {
         "psl": "^1.1.33",
         "punycode": "^2.1.1",
-        "universalify": "^0.1.2"
+        "universalify": "^0.2.0",
+        "url-parse": "^1.5.3"
       }
     },
     "tr46": {
@@ -15950,9 +15986,9 @@
       }
     },
     "universalify": {
-      "version": "0.1.2",
-      "resolved": "https://registry.npmjs.org/universalify/-/universalify-0.1.2.tgz",
-      "integrity": "sha512-rBJeI5CXAlmy1pV+617WB9J63U6XcazHHF2f2dbJix4XzpUF0RS3Zbj0FGIOCAva5P/d/GBOYaACQ1w+0azUkg==",
+      "version": "0.2.0",
+      "resolved": "https://registry.npmjs.org/universalify/-/universalify-0.2.0.tgz",
+      "integrity": "sha512-CJ1QgKmNg3CwvAv/kOFmtnEN05f0D/cn9QntgNOQlQF9dgvVTHj3t+8JPdjqawCHk7V/KA+fbUqzZ9XWhcqPUg==",
       "dev": true
     },
     "unset-value": {
@@ -16001,6 +16037,16 @@
       "integrity": "sha1-2pN/emLiH+wf0Y1Js1wpNQZ6bHI=",
       "dev": true
     },
+    "url-parse": {
+      "version": "1.5.10",
+      "resolved": "https://registry.npmjs.org/url-parse/-/url-parse-1.5.10.tgz",
+      "integrity": "sha512-WypcfiRhfeUP9vvF0j6rw0J3hrWrw6iZv3+22h6iRMJ/8z1Tj6XfLP4DsUix5MhMPnXpiHDoKyoZ/bdCkwBCiQ==",
+      "dev": true,
+      "requires": {
+        "querystringify": "^2.1.1",
+        "requires-port": "^1.0.0"
+      }
+    },
     "use": {
       "version": "3.1.1",
       "resolved": "https://registry.npmjs.org/use/-/use-3.1.1.tgz",
@@ -16124,9 +16170,9 @@
       "dev": true
     },
     "word-wrap": {
-      "version": "1.2.3",
-      "resolved": "https://registry.npmjs.org/word-wrap/-/word-wrap-1.2.3.tgz",
-      "integrity": "sha512-Hz/mrNwitNRh/HUAtM/VT/5VH+ygD6DV7mYKZAtHOrbs8U7lvPS6xf7EJKMF0uW1KJCl0H701g3ZGus+muE5vQ==",
+      "version": "1.2.4",
+      "resolved": "https://registry.npmjs.org/word-wrap/-/word-wrap-1.2.4.tgz",
+      "integrity": "sha512-2V81OA4ugVo5pRo46hAoD2ivUJx8jXmWXfUkY4KFNw0hEptvN0QfH3K4nHiwzGeKl5rFKedV48QVoqYavy4YpA==",
       "dev": true
     },
     "wrap-ansi": {
diff --git a/test/helpers.jl b/test/helpers.jl
index c61217a08b..3b745c25fc 100644
--- a/test/helpers.jl
+++ b/test/helpers.jl
@@ -16,8 +16,9 @@ import Pluto.ExpressionExplorer: SymbolsState, compute_symbolreferences, Functio
 using Sockets
 using Test
 using HTTP
-import Distributed
 import Pkg
+import Malt
+import Malt.Distributed
 
 function Base.show(io::IO, s::SymbolsState)
     print(io, "SymbolsState([")
@@ -243,8 +244,8 @@ has_embedded_pkgfiles(nb::Pluto.Notebook) =
 Log an error message if there are any running processes created by Distrubted, that were not shut down.
 """
 function verify_no_running_processes()
-    if length(Distributed.procs()) != 1
-        @error "Not all notebook processes were closed during tests!" Distributed.procs()
+    if length(Distributed.procs()) != 1 || !isempty(Malt.__iNtErNaL_get_running_procs())
+        @error "Not all notebook processes were closed during tests!" Distributed.procs() Malt.__iNtErNaL_get_running_procs()
     end
 end
 
diff --git a/test/packages/Basic.jl b/test/packages/Basic.jl
index 6a8af7e9f5..a255865c77 100644
--- a/test/packages/Basic.jl
+++ b/test/packages/Basic.jl
@@ -5,7 +5,7 @@ using Pluto.Configuration: CompilerOptions
 import Pluto: update_save_run!, update_run!, WorkspaceManager, ClientSession, ServerSession, Notebook, Cell, project_relative_path, SessionActions, load_notebook
 import Pluto.PkgUtils
 import Pluto.PkgCompat
-import Distributed
+import Malt
 
 
 @testset "Built-in Pkg" begin
@@ -13,8 +13,9 @@ import Distributed
     # We have our own registry for these test! Take a look at https://github.com/JuliaPluto/PlutoPkgTestRegistry#readme for more info about the test packages and their dependencies.
     Pkg.Registry.add(pluto_test_registry_spec)
 
-    @testset "Basic" begin
+    @testset "Basic $(use_distributed_stdlib ? "Distributed" : "Malt")" for use_distributed_stdlib in (false, true)
         🍭 = ServerSession()
+        🍭.options.evaluation.workspace_use_distributed_stdlib = use_distributed_stdlib
 
         # See https://github.com/JuliaPluto/PlutoPkgTestRegistry
 
@@ -395,8 +396,7 @@ import Distributed
     end
 
     @testset "DrWatson cell" begin
-        🍭 = ServerSession()            
-        🍭.options.evaluation.workspace_use_distributed = false
+        🍭 = ServerSession()
 
         notebook = Notebook([
             Cell("using Plots"),
@@ -446,50 +446,55 @@ import Distributed
         WorkspaceManager.unmake_workspace((🍭, notebook))
     end
 
-    @testset "File format -- Forwards compat" begin
-        # Using Distributed, we will create a new Julia process in which we install Pluto 0.14.7 (before PlutoPkg). We run the new notebook file on the old Pluto.
-        p = Distributed.addprocs(1) |> first
-
-        @test post_pkg_notebook isa String
-
-        Distributed.remotecall_eval(Main, p, quote
-            path = tempname()
-            write(path, $(post_pkg_notebook))
-            import Pkg
-            # optimization:
-            if isdefined(Pkg, :UPDATED_REGISTRY_THIS_SESSION)
-                Pkg.UPDATED_REGISTRY_THIS_SESSION[] = true
-            end
-
-            Pkg.activate(mktempdir())
-            Pkg.add(Pkg.PackageSpec(;name="Pluto",version=v"0.14.7"))
-            import Pluto
-            @assert Pluto.PLUTO_VERSION == v"0.14.7"
-
-            s = Pluto.ServerSession()
-            s.options.evaluation.workspace_use_distributed = false
-
-            nb = Pluto.SessionActions.open(s, path; run_async=false)
+    @static if VERSION < v"1.10.0-0" # see https://github.com/fonsp/Pluto.jl/pull/2626#issuecomment-1671244510
+        @testset "File format -- Forwards compat" begin
+            # Using Distributed, we will create a new Julia process in which we install Pluto 0.14.7 (before PlutoPkg). We run the new notebook file on the old Pluto.
+            test_worker = Malt.Worker()
 
-            nothing
-        end)
+            @test post_pkg_notebook isa String
 
-        # Cells that use Example will error because the package is not installed.
-
-        # @test Distributed.remotecall_eval(Main, p, quote
-        #     nb.cells[1].errored == false
-        # end)
-        @test Distributed.remotecall_eval(Main, p, quote
-            nb.cells[2].errored == false
-        end)
-        # @test Distributed.remotecall_eval(Main, p, quote
-        #     nb.cells[3].errored == false
-        # end)
-        # @test Distributed.remotecall_eval(Main, p, quote
-        #     nb.cells[3].output.body == "25"
-        # end)
+            Malt.remote_eval_wait(Main, test_worker, quote
+                path = tempname()
+                write(path, $(post_pkg_notebook))
+                import Pkg
+                # optimization:
+                if isdefined(Pkg, :UPDATED_REGISTRY_THIS_SESSION)
+                    Pkg.UPDATED_REGISTRY_THIS_SESSION[] = true
+                end
 
-        Distributed.rmprocs([p])
+                Pkg.activate(;temp=true)
+                Pkg.add(Pkg.PackageSpec(;name="Pluto",version=v"0.14.7"))
+                # Distributed is required for old Pluto to work!
+                Pkg.add("Distributed") 
+
+                import Pluto
+                @info Pluto.PLUTO_VERSION
+                @assert Pluto.PLUTO_VERSION == v"0.14.7"
+            end)
+
+            @test Malt.remote_eval_fetch(Main, test_worker, quote
+                s = Pluto.ServerSession()
+                nb = Pluto.SessionActions.open(s, path; run_async=false)
+                nb.cells[2].errored == false
+            end)
+
+            # Cells that use Example will error because the package is not installed.
+
+            # @test Malt.remote_eval_fetch(Main, test_worker, quote
+            #     nb.cells[1].errored == false
+            # end)
+            @test Malt.remote_eval_fetch(Main, test_worker, quote
+                nb.cells[2].errored == false
+            end)
+            # @test Malt.remote_eval_fetch(Main, test_worker, quote
+            #     nb.cells[3].errored == false
+            # end)
+            # @test Malt.remote_eval_fetch(Main, test_worker, quote
+            #     nb.cells[3].output.body == "25"
+            # end)
+
+            Malt.stop(test_worker)
+        end
     end
 
     @testset "PkgUtils -- reset" begin
@@ -646,7 +651,29 @@ import Distributed
 
         WorkspaceManager.unmake_workspace((🍭, notebook))
     end
-    
+
+    @testset "PlutoRunner Syntax Error" begin
+        🍭 = ServerSession()
+
+        notebook = Notebook([
+            Cell("1 +"),
+            Cell("PlutoRunner.throw_syntax_error"),
+            Cell("PlutoRunner.throw_syntax_error(1)"),
+        ])
+
+        update_run!(🍭, notebook, notebook.cells)
+
+        @test notebook.cells[1].errored
+        @test noerror(notebook.cells[2])
+        @test notebook.cells[3].errored
+
+        @test Pluto.is_just_text(notebook.topology, notebook.cells[1])
+        @test !Pluto.is_just_text(notebook.topology, notebook.cells[2]) # Not a syntax error form
+        @test Pluto.is_just_text(notebook.topology, notebook.cells[3])
+
+        WorkspaceManager.unmake_workspace((🍭, notebook))
+    end
+
     @testset "Precompilation" begin
         compilation_dir = joinpath(DEPOT_PATH[1], "compiled", "v$(VERSION.major).$(VERSION.minor)")
         @assert isdir(compilation_dir)
@@ -744,4 +771,3 @@ end
 
 # LibGit2.checkout!(repo, "aef26d37e1d0e8f8387c011ccb7c4a38398a18f6")
 
-
diff --git a/test/runtests.jl b/test/runtests.jl
index 3b3ce21a51..88901d4ae3 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -10,7 +10,7 @@ if get(ENV, "PLUTO_TEST_ONLY_COMPILETIMES", nothing) == "true"
 end
 @timeit_include("Events.jl")
 verify_no_running_processes()
-@timeit_include("WorkspaceManager.jl")
+@timeit_include("Configuration.jl")
 verify_no_running_processes()
 @timeit_include("packages/Basic.jl")
 verify_no_running_processes()
@@ -30,7 +30,7 @@ verify_no_running_processes()
 verify_no_running_processes()
 @timeit_include("Notebook.jl")
 verify_no_running_processes()
-@timeit_include("Configuration.jl")
+@timeit_include("WorkspaceManager.jl")
 verify_no_running_processes()
 
 # tests that don't start new processes:
diff --git a/test/webserver.jl b/test/webserver.jl
index 0d94e1887c..009ff34631 100644
--- a/test/webserver.jl
+++ b/test/webserver.jl
@@ -32,25 +32,21 @@ using Pluto.WorkspaceManager: WorkspaceManager, poll
         base_url,
     )
     🍭 = Pluto.ServerSession(; options)
-    server_task = @async Pluto.run(🍭)
+    server = Pluto.run!(🍭)
 
-    # FYI, you should normally use a PlutoEvent for things we do in this test instead of polling! Don't use this as an example.
-    @test poll(10) do
-        server_running()
-    end
+    @test server_running()
 
-    sleep(20)
-    @test HTTP.get("http://$host:$port/edit"; status_exception=false).status == 404
+    sleep(3)
+    @test poll(20) do
+        # should not exist because of the base url setting
+        HTTP.get("http://$host:$port/edit"; status_exception=false).status == 404
+    end
 
     for notebook in values(🍭.notebooks)
         SessionActions.shutdown(🍭, notebook; keep_in_session=false)
     end
 
-    schedule(server_task, InterruptException(); error=true)
-
-    # wait for the server task to finish
-    # normally this `wait` would rethrow the above InterruptException, but Pluto.run should catch for InterruptExceptions and not bubble them up.
-    wait(server_task)
+    close(server)
 end
 
 @testset "Exports" begin
@@ -69,14 +65,16 @@ end
 
 
     # without notebook at startup
-    options = Pluto.Configuration.from_flat_kwargs(; port, launch_browser=false, workspace_use_distributed=true, require_secret_for_access=false, require_secret_for_open_links=false)
+    options = Pluto.Configuration.from_flat_kwargs(; 
+        port, launch_browser=false, 
+        workspace_use_distributed=true, 
+        require_secret_for_access=false, 
+        require_secret_for_open_links=false
+    )
     🍭 = Pluto.ServerSession(; options)
-    server_task = @async Pluto.run(🍭)
+    server = Pluto.run!(🍭)
     
-    # FYI, you should normally use a PlutoEvent for things we do in this test instead of polling! Don't use this as an example.
-    @test poll(10) do
-        server_running()
-    end
+    @test server_running()
     
     @test isempty(🍭.notebooks)
     
@@ -112,10 +110,7 @@ end
         SessionActions.shutdown(🍭, notebook; keep_in_session=false)
     end
     
-    schedule(server_task, InterruptException(); error=true)
-    # wait for the server task to finish
-    # normally this `wait` would rethrow the above InterruptException, but Pluto.run should catch for InterruptExceptions and not bubble them up.
-    wait(server_task)
+    close(server)
 end
 
 end # testset