Open Source Licenses

View the open source licenses used in Checkmate's platform. Understand our commitment to transparency and collaborative software development.

Open Source Licenses & Acknowledgments

Checkmate is built upon the shoulders of giants, utilizing a variety of open-source software that enables us to deliver a world-class chess experience. We're deeply grateful to the developers and contributors of these projects.

Specifically, Checkmate utilizes:

• JaVaFo: A pairing engine implementing the FIDE (Dutch) System, as described in the FIDE handbook (chapter C.04.3). JaVaFo is authored and intellectually owned by Roberto Ricca, former programmer, International Arbiter and current Secretary of the FIDE Commission "Systems of Pairings and Programs" (SPPC).

• Stockfish 16.1: A leading open-source chess engine renowned for its strong playing ability and advanced neural network-based evaluation. This enables Stockfish to assess chess positions with remarkable accuracy.

Important Note: While Stockfish is a valuable tool for learning and analysis, its use during live games is strictly prohibited and considered a form of cheating. Our Fair Play system actively monitors for the use of Stockfish and other chess engines to maintain the integrity of our platform.

We believe in the power of open source and are committed to supporting and contributing back to the community whenever possible.