Credits

Design

• Custom interface design — BemBuPlol

Assets

• Move and capture sound effects — Thibault Duplessis (Standard sound set)
• Chess piece design — Colin M. L. Burnett (“cburnett” set, via Lichess), GPLv2+
• Site's icons & logo — BemBuPlol
• Icons design — Causa

Chess Engine

Game review and Coach games run in your browser using Stockfish 19 Lite (single-threaded WebAssembly build: stockfish-19-lite-single.js and stockfish-19-lite-single.wasm), packaged by Stockfish.js (© Chess.com, LLC, GPLv3).

Stockfish is a free and open-source chess engine developed by the Stockfish community and licensed under the GNU GPL v3. Source code.

Lightness 1.0 is a lightweight chess engine written and maintained by BemBuPlol, bundled as an optional engine alongside Stockfish. Can be used for coach and for reviews, but don't expect it to be fast or as accurate as stockfish.

Data & libraries

• Public game import — Chess.com Published-Data API and the Lichess API
• Move validation — chess.js (© Jeff Hlywa, BSD-2-Clause) and python-chess (© Niklas Fiekas, GPL-3.0+)
• Opening book — Performance.bin by Marc Lacrosse
• Opening names — lichess-org/chess-openings (CC0)

Contact

Questions, bug reports, or feedback about Lightness Review or the Lightness 1.0 engine: .