I'd like to announce the REMIX THIS GAME contest.

http://dto.github.com/notebook/remix-this-game.html

REMIX THIS GAME is an experimental game design contest where participants can re-mix and re-cycle my free-software self-published PC game, XONG. XONG is available under permissive licenses allowing remixes and derivative works of the code, graphics, sound effects, and music—even for commercial use. The source code license is the GNU GPL Version 3, and the media is covered by the Creative Commons BY-SA license.

No special software or programming experience are needed—XONG has been packaged up so that you can just download the game and edit the graphics/code/music/sounds in place, and re-start the game to see your changes. Plus, it is available for Windows, Mac OSX, and GNU/Linux, so you can remix it on whichever OS you use, using whatever programs you like.