Licenses
ChessPillar distributes the third-party software listed here. Each entry names the exact version served and links to its licence and source.
Stockfish
Fight the Position plays against Stockfish, which runs entirely in your browser. It is licensed under the GNU General Public License version 3.
- Package
- stockfish 18.0.8 (npm)
- Builds served
stockfish-18-lite-single.jsstockfish-18-single.js- Variants
- Stockfish 18 WebAssembly, single-threaded: the lite build by default and the full NNUE build when a reader chooses it. Both are the same package release.
- Modifications
- None. The files are served byte-for-byte as published.
- Licence text
- GPL-3.0, as shipped with this build
Stockfish is the work of T. Romstad, M. Costalba, J. Kiiski, G. Linscott and contributors. The WebAssembly build is maintained by nmrugg and Chess.com, LLC. ChessPillar is not affiliated with either.
Board and pieces
The interactive board is laid out by react-chessboard (MIT) and chess rules are handled by chess.js (BSD-2-Clause). The piece artwork is not theirs: every board in ChessPillar draws one of the sets below.
- Set
- Classic
- Artwork
- Colin M. L. Burnett
- Licence selected
- BSD-3-Clause
- Source
- Wikimedia Commons
Cburnett is multi-licensed by its author on Wikimedia Commons — GFDL, CC BY-SA 3.0, BSD and GPL, with the licence left to the user’s choice. ChessPillar takes the files from Commons and selects BSD. The same artwork is also distributed by Lichess under GPLv2+; that is a different grant, and it is not the one relied on here.
Typefaces
Three font families are self-hosted and served from this site rather than fetched from a third party: Golos Text for the interface, Literata for reading, and JetBrains Mono for machine text, all under the SIL Open Font License 1.1. No request for a font leaves your browser.
Corresponding source
The download above is the source package prepared for the exact Stockfish files this site serves. It includes the pinned WASM build source, build configuration, GPL text and the NNUE input embedded in this lite build. ChessPillar copies the distributed files unchanged.