# Stockfish on ChessYard

This directory ships an unmodified Stockfish.js 18 **lite single-thread** WebAssembly build for browser vs-AI play.

## Upstream

- Stockfish chess engine (NNUE): https://github.com/official-stockfish/Stockfish  
  Authors include Tord Romstad, Marco Costalba, Joona Kiiski, Gary Linscott, and many contributors.
- Browser / WASM packaging (stockfish.js): https://github.com/nmrugg/stockfish.js  
  Copyright Chess.com, LLC and contributors (Nathan Rugg et al.).
- NNUE nets used by Stockfish releases are published via the Stockfish testing framework (see engine release notes).

## Licence

Both Stockfish and stockfish.js are licensed under the **GNU General Public License v3.0**.  
The full licence text is in `COPYING` in this folder.

You can obtain the corresponding source for the engine and the WASM packaging from the upstream repositories linked above. This site uses the public `v18.0.0` lite-single release artifacts without modifying their binary contents.

## Files

- `stockfish-18-lite-single.js` — Worker entry (UCI over `postMessage`)
- `stockfish-18-lite-single.wasm` — WASM binary (~7MB)
- `COPYING` — GPLv3 text from Stockfish

Stockfish and its authors do not endorse this site. Local AI is for practice only.