If you lack human opponents, you can try Toss, but it is currently going through important stages of AI development so you might want to wait till a future release (or try out the svn version, visit our mailing list, etc.)
If you lack human opponents, you can try Toss, but it is currently going through important stages of AI development so you might want to wait till a future release (or try out the svn version, visit our mailing list, etc.)