Licences and credits
Chess engine
ChessDays runs Stockfish 19 in your browser, using the unmodifiedstockfish-19-lite-single build of Stockfish.js 19.0.0. Stockfish is free software under the GNU General Public License, version 3.
If that link stops working, write to contact@mussiehaile.com and we will send you a copy of the source.
Chess pieces
The piece artwork comes with react-chessboard and is based on the chess pieces by Colin M.L. Burnett (Cburnett), used under the3-clause BSD licence.
Chess puzzles
The daily chess puzzles are a filtered selection from theLichess puzzle database, released under theCC0 1.0 public domain dedication. Credit is not required, but we are glad to give it: thank you to Lichess and its players. ChessDays is not connected to Lichess.
Software and fonts
| Name | Used for | Licence |
|---|---|---|
| chess.js | chess rules | BSD 2-Clause |
| React | interface | MIT |
| react-chessboard | the board | MIT |
| canvas-confetti | win effects | ISC |
| Inter | font | SIL OFL 1.1 |
| Fraunces | font | SIL OFL 1.1 |
| JetBrains Mono | font | SIL OFL 1.1 |
Sounds and characters
The game sounds and character voices are synthesized in your browser. The characters are original drawings.