Open source licenses · Chess Drills

StockfishGPL v3

Chess engine for Play and the engine arrow. Used unmodified, as a separate program (stockfish.js 10.0.2).

License text · Stockfish source code · stockfish.js source code

Chess pieces "cburnett"BSD

By Colin M.L. Burnett.

chess.jsBSD 2-Clause

Chess rules and move validation, by Jeff Hlywa.

License text · Source

chessboard.jsMIT

The chess board, by Chris Oakman.

License text · Source

jQueryMIT

JavaScript helper library.

License text · Source

InterSIL Open Font License 1.1

Typeface by Rasmus Andersson.

License text · Source

LucideISC

Icons.

License text · Source

Data sources

Opening statistics come from the lichess.org opening explorer. Opening names come from the lichess chess-openings list (CC0). Chess Drills is not affiliated with Lichess.