Credits and licences
This site relies on free software, data and artwork. This page is generated automatically from our source registry.
Stockfish 19 — Stockfish.js (build WebAssembly « lite single »)
Author : The Stockfish developers ; build web : Nathan Rugg / Chess.com · Licence : GPL-3.0-only
Analysis engine running in your browser as a separate, unmodified program (worker). Corresponding source: tag v19.0.0.
Stockfish is distributed unmodified, as a separate program. Its corresponding source code is available at the link above.
Stockfish (projet officiel)
Author : The Stockfish developers · Licence : GPL-3.0-only
Upstream engine of Stockfish.js; Stockfish 19 (official, unmodified binary) also analyses imported games on the coach's computer, as a separate program.
chess.js
Author : Jeff Hlywa · Licence : BSD-2-Clause
Game rules, legal moves, game parsing (PGN).
Chessnut (jeu de pièces)
Author : Alexis Luengas (© 2015) · Licence : Apache-2.0
Piece and mascot drawings until 13/10/2026 (replaced by the “citron” pieces; files kept).
Formule des chances de gain (Lichess)
Author : Lichess · Licence : Formule mathématique publiée (non protégeable) ; code Lichess AGPL-3.0 non utilisé
Turning engine evaluations into winning chances.
Next.js, React, Tailwind CSS
Author : Vercel, Meta, Tailwind Labs · Licence : MIT
Building the website.
web-push
Author : Marco Castelluccio et contributeurs · Licence : MPL-2.0
Sending reminders (notifications) from the server.
lichess-org/chess-openings
Author : Lichess et contributeurs · Licence : CC0-1.0
Opening names and ECO codes, and the move where the game leaves theory (data/openings.json, 2026-09-20 version).
Base de puzzles Lichess
Author : Lichess · Licence : CC0-1.0
Puzzles by theme and difficulty (phases 3–4).
API publique Lichess (parties des joueurs)
Author : Lichess · Licence : CC0-1.0 (parties Lichess, domaine public) ; API publique
Importing a Lichess player's public games.
Base de finales Syzygy (API publique Lichess)
Author : Ronald de Man (tables Syzygy), Lichess (service) · Licence : Résultats exacts de positions (faits mathématiques, non protégeables) ; API publique Lichess
Exact result of endgames with 7 pieces or fewer (win, draw, loss).
Chess.com Published-Data API
Author : Chess.com · Licence : Conditions d'utilisation Chess.com
Importing a player's public games.
Legal check in progress.
Base des parties Lichess (fichiers mensuels)
Author : Lichess · Licence : CC0-1.0
Opening statistics by level: moves played and results, from a sample of September 2026 rated games (blitz, rapid, classical). Only the statistics are kept, not the games.
ChessGoals — comparaison des classements
Author : ChessGoals · Licence : Faits publiés (correspondances de classements), cités avec attribution
Approximate mapping between Chess.com and Lichess ratings, to pick the level band of opening statistics.
José Raúl Capablanca, Chess Fundamentals (1921, édition révisée de 1934)
Author : José Raúl Capablanca · Licence : Public domain (France : auteur mort en 1942)
Passages quoted by the library and, later, by the assistant (with chapter and page).
Howard Staunton, The Blue Book of Chess (édition révisée de 1910)
Author : Howard Staunton ; révision : John C. Winston Company · Licence : Public domain (France : auteur mort en 1874 ; révision anonyme de 1910)
Passages quoted by the library and, later, by the assistant (with chapter and page).
François-André Danican Philidor, L'Analyze des Échecs (1749)
Author : François-André Danican Philidor · Licence : Public domain (France : auteur mort en 1795)
Passages quoted in French ("pawns are the soul of chess"), with the page of the 1749 edition.