Code that I've written which you're free to use, modify, and redistribute according to the various open source licenses each project is under:

• heylisten - Rough scripts for recognizing notes and note sequences from real-time input (on Linux).
• textension - An Inform-like language/interpreter for writing IF that allows explicit movement through time. Very much still under development.
• ORE - The code for the Occupancy-Regulated Extension library for procedural content generation. ORE provides a content generation engine that generates detailed geometry and allows constrained emergence.
• All You Base Is Belong To Us - My team's submission for the 2011 Global Game Jam. It's a pretty fun one- or two-player game that combines tower defense with castle defense. Requires Python 3.1 and Pygame 1.9.1 (the version that works with Python 3.1).
• Toponaut - My prototype for Noah Wardrip-Fruin's Playable Media class in the Winter Quarter of 2011. This is a game engine along with a bit of content for it. The game can be summarized as a fractal puzzle-platformer. (This doesn't have license text yet, but that should be fixed soon)