The Indie Gam Jam is a “yearly game design and programming event designed to encourage experimentation and innovation in the game industry. A very small volunteer team of professional game developers creates a new custom game engine with a single technology focus, and then we invite a slightly larger group of game programmer-designers to get together and make as many innovative games as possible over a four-day period. The games are shown at the Experimental Gameplay Workshop at the Game Developers Conference, and the code is released on SourceForge under the GNU General Public License, so everyone can freely experiment with the engine source code and games.”
They just had their first show, and created 12 games in four days!