RoboWar is an virtual arena where programmed robots fight to the death using a variety of weapons and techniques. The robots are programmed using a stack-oriented programming language called RoboTalk. The robots are also configured using a set of hardware features, and the sum of the features determines the robot's class.
According to Wikipedia's article on RoboWar, "25 RoboWar tournaments were held in the past between 1989 until roughly 2003, when tournaments became intermittent and many of the major coders moved on." You can still download the original RoboWar application and pit tournament-winning robots against each other. A random selection of those robots have been made available JSRoboWar.
I wrote JSRoboWar as a programming exercise. I'm not devoting a lot of time to developing it, but feel free to fork it on GitHub and send me patches.