Open-source licences

Knightfall's board, piece artwork, bot characters and interface are original. It builds on these open-source projects:

• Stockfish 19 (stockfish.js WebAssembly build)

  GPL-3.0

  Runs unmodified as a separate program in a Web Worker. Licence text is served at /engine/COPYING.txt.

  Source code

• chess.js

  BSD-2-Clause

  Move generation and rules validation.

  Source code

• Next.js, React, Zustand, Tailwind CSS

  MIT

  Application framework and libraries.

  Source code

• Firebase JavaScript SDK

  Apache-2.0

  Accounts and progress sync.

  Source code

• lichess-org/chess-openings

  CC0-1.0

  Opening names and ECO codes for the explorer, classification and repertoire trainer.

  Source code

• Lichess tablebase API (Syzygy tablebases)

  Public web service

  The endgame trainer looks up positions with up to seven pieces at tablebase.lichess.ovh. No tablebase files are distributed.

  Source code

• Inter, Space Grotesk, JetBrains Mono

  SIL Open Font License 1.1

  Interface typefaces via Google Fonts.

  Source code