When looking for a game for New Year's Day (see last post ;-)) I stumbled
on continuation of RoboCode -- RoboCodeNG. The first thought I got when I first saw robot team API was: "Wow! How much neater could computer science laboratories be if we could implement byzantene agreement solutions in RoboCode instead of PVM!" ;-)
Some details about this game: It is Java based, you write robot code in pure Java ( you can use Eclipse/NetBeans/IDEA/... for it ) and it is somewhat similar to corewars -- you have an arena where robots makes fights. As very nice addition you can have teams of robots cooperating with each other.