Arasan is a chess program for Windows and Linux. It has both a native user interface (for Windows only) and a console-based chess engine for use with Winboard or xboard.
DigWords is a Crossword style board game using familiar Scrabble-like word building rules. A game lasts for just 12 rounds, with a fresh set of 7 letters in each round.
pouetChess is a small 3D chess game for beginners. It features single and two player modes, a strong and fast AI, pretty graphics, low end hardware support, and is completely open source and free.