I'm looking for a game which will allow me to test various artificial intelligence, reinforcement learning and machine learning algorithms. It would be great, if there will be good documentation or even helpful framework for writing AI. I know about TORCS, but do you know other games? It doesn't matter in which language it is written. It can be any arcade game, simulator, FPS, etc.
Quake 3 is an ideal candidate for bot design. 

open source code base.
Realistic scenario (compared to robocode which is a toy domain).
existing bots and I believe the first bots used in Quake 3 where the output of a Ph.D.
lots of documentation.
Game which allows to test AI algorithms