Open source

Stockfish in ChessWOW

ChessWOW analyzes positions and games with Stockfish 19, the free chess engine by the Stockfish developers. Stockfish is licensed under the GNU General Public License version 3 (GPLv3).

Source code

The complete source code of the engine as it runs in the app on iOS, iPadOS, macOS and Android, including our changes, is published at github.com/chesswow/stockfish.

The repository lists every change compared to the original Stockfish 19, shows how to check that all other files are identical and explains how to build the engine.

What we changed

The engine runs inside the app instead of as a separate program. For this we replaced its start file, connected its input and output to the app and made sure that an invalid command no longer closes the app.

The chess itself is unchanged: same search, same evaluation, same neural network as Stockfish 19.

Licence texts

The licence texts of all open source components are in the app under Licences. The GPLv3 is also available at www.gnu.org/licenses/gpl-3.0.html.

Contact

Questions about the source code: contact@chesswow.app