Interactive Activities: Combinatorial Games - Java implementations of several impartial, partizan, and one-player games garnered from the books Winning Ways and On Numbers and Games. - http://www.cut-the-knot.com/Curriculum/index.html#games
GAMESMAN - Game-independent Automatic Move/position-tree Exhaustive-Search, Manipulation And Navigation. Tool for analyzing and playing small two-player games, built independent of the actual game being played. - http://www.cs.berkeley.edu/~ddgarcia/software/gamesman/