[spicybright]

I didn't think this was much, just some kind of chess rules engine, but this program also implements an AI opponent to play against.

That's insanely impressive!

[actually_a_dog]

Not just “an” AI opponent, either, but a fairly sophisticated one.

https://www.chessprogramming.org/Alpha-Beta

https://www.chessprogramming.org/Quiescence_Search