Shaderfrog

Shaderfrog is a shader editor and composer by Andy Ray that lets you write GLSL in nodes and combine shaders in a graph editor instead of merging them by hand. Version 2.0 reaches beyond Three.js to Babylon.js and PlayCanvas, and the community gallery holds thousands of shaders to open and remix, with a featured selection on the homepage. Start with the about post, where Andy explains that he built the first version to combine a water shader with light rays for the underwater background of a WebGL game.