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