I found Robocode through my AP Computer Science A class. I fiddled around with it a little but never did much. I introduced Kinsen to RoboCode when I was in APCS A.
I've helped Kinsen with his robots and talked about design. I also try to make him use good coding style and document things.
Currently, I'm working on a Robocode project with him.
Language design is interesting but compilers can be touchy things.