The logic of handling a chessboard and parsing standard
FEN (Farnsworth-Edwards Notation) for describing a position as well as SAN
(Standard Algebraic Notation) for describing individual moves is handled. This
class can be used as a backend driver for playing chess, or for validating
and/or creating PGN files using the File_ChessPGN package.

WWW: http://pear.php.net/package/Games_Chess/