I don't know all but the Chess.app is actually one, running the sjeng engine which is GPLv2 licensed https://github.com/apple-oss-distributions/Chess/tree/Ches

I don't know all but the Chess.app is actually one, running the sjeng engine which is GPLv2 licensed https://github.com/apple-oss-distributions/Chess/tree/Chess-524.22/sjeng https://github.com/apple-oss-distributions/Chess/tree/Chess-... https://sjeng.org/indexold.html https://sjeng.org/indexold.html