KBoard is a generic game interface for two player turn based board games, and currently supports a bunch of chess variants, connect four, reversi and chain reaction (and more will be added). Kboard also supports network chess play on ics servers, as well as game observation and examination. It features a quite powerful generic animation engine, and a highly customizable theme specification (based on lua), that can just load everything and create shadows. Easy pgn game editing is supported.

License: free