The Stockfish project has announced that it reached a settlement in the legal dispute with ChessBase, which was accused of violating the GPLv3 license by incorporating code from the free chess engine Stockfish into its proprietary products Fat Fritz 2 and Houdini 6 without releasing the source code of the derivative work and without informing clients about the use of GPL code. The settlement provides for the withdrawal of ChessBase's revocation of the GPL license for Stockfish code and allows the company to distribute its software.
As part of the reached agreement, ChessBase will cease the sale of chess programs that use the Stockfish engine and will inform clients through a publication on its website. Existing clients will be able to continue using already purchased programs and will also be able to download previously acquired copies if ChessBase aligns its download process with GPL requirements. One year after the settlement, the Stockfish developers will withdraw the GPL license revocation and allow ChessBase to use their code, as the company has recognized the value and potential of free software and committed to adhering to its principles.
The GPL allows for the revocation of a license from an infringer and the termination of all rights granted to the licensee under that license. According to the termination rules accepted in GPLv3, if violations are detected for the first time and corrected within 30 days of notification, the license rights are restored, and the license is not fully revoked (the contract remains unviolated). Rights are also immediately restored if violations are corrected and the rights holder did not notify of the infringement within 60 days. If deadlines are missed, the license violation can be interpreted as a breach of contract, for which the court may grant relief.
To prevent possible violations in the future, ChessBase will appoint a dedicated employee to monitor compliance with GPL requirements. The company will also create a website, foss.chessbase.com, where information about products using open code will be published. Additionally, ChessBase will release implementations of neural networks, supplied for use with Stockfish, under GPL or a compatible license. The agreement does not provide for any financial compensation or damages, as the Stockfish project team represents a nonprofit community that has been advocating for GPL compliance and its rights.
Source: opennet.ru
