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.
JSRoboWar is a from-scratch port of RoboWar to JavaScript. JSRoboWar supports most of the functionality of the original except for teamplay, custom icons and sounds, lasers (which are deprecated anyway), debugging, and a Hardware Depot (every bot has the same large feature set). It uses the Raphaël JavaScript Library to draw to an HTML5 canvas.
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.