A great go ai – Little Go Review

Little go is a well designed program with a fun ai to play against as a practice partner. Admittedly the default ai (even "fuego weak") can be a bit daunting for beginners but you can specify your own custom ai settings and can also give yourself up to a 9 stone handicap. I have found that since the ai will resign once the game is lost I never really fully practiced the endgame. Against humans I lost a lot of endgames due to careless moves. You can specify a no-resign ai to play against though (resign behavior is customizable)
Review by Light cloud on Little Go.