Throughout history, chess has seen fierce rivalries play out, but perhaps none like this. The open source Stockfish chess engine has filed a lawsuit against ChessBase, accusing it of violating the GPL 3 licence Stockfish is shared under, with ChessBase’s Fat Fritz 2 chess engine. This, the Stockfish team claim, is a derivative of Stockfish, but with some new lines of code and proprietary features.
In an announcement regarding the lawsuit (
https://bit.ly/lxf280stockfish), the Stockfish team state that “ChessBase repeatedly violated central obligations of the GPL, which ensures that the user of the software is informed of their rights.”