MFScript Console (previously MFS JS Console) is a userscript that adds a toggleable CLI on the top right corner of your pages, which in turn interprets my home-brewn MFScript.
The syntax and features of MFScript is inspired by the syntax of the Quake/GoldSrc/Source engines' command line options, their in-game console commands, and Minecraft's in-game commands.
The intent of this script is to allow quick runtime behaviours be run in web pages, such as grabbing the images, without having to write JavaScript or find userscripts that run on specific websites.
Click here to install as user script. Greasemonkey 3.* is the preferred user script extension.
See the wiki for more detailed documentation.
MFScript Console is licensed under MIT License. Read the license in full here.