https://en.wikipedia.org/wiki/Blondie24
https://www.amazon.com/Blondie24-Playing-Kaufmann-Artificial...
(Edit) One of the funniest parts I remember is that they had to leave it running on a Pentium III for like a month or something.
There is also Deep Blue[1], which is famous for once defeating Garry Kasparov in a high profile match.
[0] http://www.amazon.com/Blondie24-Playing-Kaufmann-Artificial-... [1] http://en.wikipedia.org/wiki/Deep_Blue_%28chess_computer%29
http://www.amazon.com/Blondie24-Playing-Kaufmann-Artificial-...
They partially trained their checkers algorithm by playing it online against humans. The funny part was that they couldn't get many opponents until they changed their handle to Blondie24, then game requests came flooding in...
For an even shorter, and lighter, read on checkers engine, I recommend Blondie24[0].
[0] https://www.amazon.com/dp/1558607838