Stratagus is a really fun RTS game for linux and windows. And yes, you can download the source. You can download the source and the actually game from here:http://stratagus.sourceforge.net/download.shtml. I don't really know anything about programing or compatability with the GP2X, but I figured it runs on linux and is open source so why not? Anyway, I think it would be really cool for somebody to port this game.