This is a web encyclopedia of graphical programs and demonstrations. They all include a small file tinywebgl-ucla.js, a tutorial file from UCLA's Graphics Programming class that minimally sets up a WebGL 3D drawing program for any purpose.
Each demo/article in this encyclopedia shows a scene, made by a single subclass of Scene_Component from tiny-graphics.js. Users can view the source of each Scene_Component subclass, and easily code and contribute their own in the same textbox, submitting a new article to the database for all to see.
You can write and submit more classes to the database (besides just scenes), and then depend on those later in your actual Scene_Component. Two more classes from tinywebgl-ucla.js you might want to subclass are Shape and Shader.