Java Chess and other Boardgames engines ??

Hello!

I have an boardgames site on a build, as im limited, so i personally cant offer a possibility to play
boardgames against computer, i was thinking that maybe there is a chance that some other folks have
already build open source Chess, Checkers, etc, etc… engines.

I would like to ask, about, the most common open/free boardgame engines there is for Java.

As im also a very beginner with Java, i would love to have the engines to be that simple that
i could just enter an board situtation and computer would return an move and engine itself
could be on a .JAR file.

Im not very good English reading person, so i wanted to ask here at the Java forums.

Open Source Java engines for Boardgames : Chess, Checkers, CrossCheckers and all the others ??

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Thanks,