Gibber is a live coding environment for the web browser, using the Gibberish.js audio engine, the CodeMirror code editor library and wrapping Three.js for 3d graphics and shader support. Version 2 of Gibber features a much more efficient audio engine, some interesting mapping abstractions and a server/database backend for publishing and browsing files and collaboratively live coding.
LÖVE is a framework for making 2D games in the Lua programming language. LÖVE is totally free, and can be used in anything from friendly open-source hobby projects, to evil, closed-source commercial ones.