As announced nearly one year ago, leading Stockfish developers have filed suit against ChessBase to enforce their license termination after repeated copyright violation by ChessBase. The court hearing in the case Tord Romstad and Stéphane Nicolet vs. ChessBase GmbH will take place soon.
In recent months, we have presented to the court detailed evidence that the ChessBase products Houdini 6 and Fat Fritz 2 have copied extensive parts of the Stockfish code base authored by the plaintiffs and that ChessBase repeatedly violated central obligations of the GPLv3 license. GPLv3 requires that the user is informed of their rights, has access to the corresponding sources, and has the right to reproduce, modify and distribute GPLed programs royalty-free.
We have applied to the court to order ChessBase to cease distributing Stockfish in all forms, including Fat Fritz 2 and Houdini 6, as the GPLv3 license has been terminated permanently according to section 8, and to cover our legal expenses.