marcos-projects

Licensing of Marco’s Chess

Everything in this folder (marco-chess/) is free software under the GNU General Public License, version 3 or (at your option) any later version. The full text is in LICENSE.

The rest of marcos-projects is Apache-2.0 (see ../LICENSE). This folder is different because the game ships the Sjeng chess engine, which is GPL.

The chess engine: Sjeng

• Sjeng 11.2, Copyright (C) 2000–2001 Gian-Carlo Pascutto, originally based on Faile, Copyright (c) 2000 Adrien M. Regimbald. Licensed under the GPL, version 2 or (at your option) any later version; used here under version 3.
• This copy comes from Apple’s open-source release of macOS Chess (apple-oss-distributions/Chess, tag Chess-570.1). Apple’s notice is kept in sjeng/src/COPYING.
• It has been modified to run in a web browser. Every change is listed in sjeng/README.md and marked in the source.

Marco’s Chess is not affiliated with or endorsed by Apple or by the authors of Sjeng.

Source code for the WebAssembly engine

js/sjeng/sjeng.js and js/sjeng/sjeng.wasm are compiled from the sjeng/ folder by sjeng/build.sh. That folder is the complete corresponding source, and it is published on the website next to the game itself.

The rest of the game

The rules, board and controls (chess.html, chess.css, js/) are by Marco Seman, under the same GPL-3.0-or-later.