ChessDB - ChessDB - a free Chess database for Mac OS X, Windows, Linux, and UNIX - like ChessBase, but better
Halfchess - Learn to be a better Chess player, playable in your browser
DecodeChess - AI chess tutor and analysis
Perfect Circle - Test your designer skills!
Chess Tempo Database - Chess Tempo Database gives you a library of more than 2 million searchable chess games.
Knight Maneuver - A mini chess game