Credits
Shahmat.org is built on top of several open-source projects and open datasets. We're grateful to their authors and maintainers, and we credit them here as their licenses require.
Chess pieces — the "cburnett" set
The chess piece artwork used across the site was created by Wikipedia/Wikimedia Commons contributor Cburnett, and is the same widely-used set found on Wikipedia and Lichess.
CC BY-SA 3.0 / GFDLChess pieces — the "merida" set
An optional piece style (Settings → Piece Style) created by Armando Hernandez Marroquin, bundled via the open-source Lichess project (lichess-org/lila).
GNU GPL v2 or laterChess pieces — the "chessnut" set
An optional piece style (Settings → Piece Style) created by Alexis Luengas, bundled via the open-source Lichess project (lichess-org/lila).
Apache License 2.0Chess pieces — the "celtic" set
An optional piece style (Settings → Piece Style) created by Maurizio Monge, bundled via the open-source Lichess project (lichess-org/lila).
MIT LicenseChess pieces — the "fantasy" set
An optional piece style (Settings → Piece Style) created by Maurizio Monge, bundled via the open-source Lichess project (lichess-org/lila).
MIT LicenseChess pieces — the "spatial" set
An optional piece style (Settings → Piece Style) created by Maurizio Monge, bundled via the open-source Lichess project (lichess-org/lila).
MIT LicenseChess pieces — the "firi" set
An optional piece style (Settings → Piece Style) created by James Faure, bundled via the open-source Lichess project (lichess-org/lila).
CC BY 4.0Chess pieces — the "kiwen-suwi" set
An optional piece style (Settings → Piece Style) created by neverRare, bundled via the open-source Lichess project (lichess-org/lila).
CC BY 4.0Chess pieces — the "rhosgfx" set
An optional piece style (Settings → Piece Style) created by RhosGFX, bundled via the open-source Lichess project (lichess-org/lila).
CC0 1.0 (Public Domain)Chess pieces — the "Şahî" (Shahi) sets
Two optional piece styles (Settings → Piece Style: "Shahi Ivory & Brown" and "Shahi White & Gray") created by Tamer Karatekin / DeepSeaChess LLC, depicting historical Persian/Middle-Eastern chess and shatranj artwork. Unlike the other piece sets on this page, these are used unmodified under their own custom license, not a standard open-source one -- it permits personal and commercial use, but prohibits altering the artwork or file names/metadata in any way. The full license text ships alongside the files at /assets/pieces/shahi-LICENSE.txt.
Şahî Font License v1.0 (custom, no-modification)Move, capture & check sound effects
The short sound effects that play on a move, capture, check, or game end (Settings → Sound) were created by Enigmahack, part of the "sfx" sound theme bundled via the open-source Lichess project (lichess-org/lila).
GNU AGPL v3 or laterStockfish — chess engine
Bots you play against are powered by Stockfish, one of the strongest open-source chess engines in the world, created by T. Romstad, M. Costalba, J. Kiiski, G. Linscott, and the wider Stockfish community. The in-browser build we use is the WebAssembly port maintained by nmrugg.
GNU GPL v3chess.js — rules & move generation
Legal-move validation and game-state tracking are handled by chess.js, created by Jeff Hlywa.
BSD 2-ClauseThree.js — 3D rendering
The optional 3D board (Settings → Revolution) is rendered with Three.js, an open-source WebGL library maintained by the three.js authors and contributors.
MIT LicensePuzzle database
Puzzles in the Puzzles Hub come from the Lichess puzzle database, a community-sourced collection released into the public domain by Lichess.org.
CC0 (Public Domain)Shahmat.org is an independent project and is not affiliated with or endorsed by Lichess, Chess.com, Wikipedia, or the Stockfish team.