GNU GENERAL PUBLIC LICENSE v3.0 · RELEASE v1.0.0

Sixty-Four Chess Engine — Open Source Core (GPLv3)

The standalone UCI engine binary (sixty_four_engine.exe) bundled with Sixty-Four is free software licensed under the GNU General Public License v3.0.

Complete Corresponding Source Archive (v1.0.0)

Includes bin/sixty_four_engine.dart, lib/engine/ (23 pure-Dart modules), LICENSE (GPLv3), and README.md.

File: sixty-four-engine-src-v1.0.0.zip

Download Source (.zip)

Build Instructions (Dart SDK)

The engine is written in pure Dart with zero external package dependencies. You can compile a standalone native executable on Windows, macOS, or Linux using the standard Dart SDK (^3.10.0):

# 1. Extract the source archive
unzip sixty-four-engine-src-v1.0.0.zip
cd sixty-four-engine-src-v1.0.0

# 2. Compile the standalone native UCI executable
dart compile exe bin/sixty_four_engine.dart -o sixty_four_engine.exe

# 3. Verify UCI handshake
./sixty_four_engine.exe
uci
isready
position startpos
go depth 8
quit

Architecture & Upstream Credits

Board Representation: 64-bit Magic Bitboards with precomputed sliding attack tables, Zobrist hashing, and copy-make state stack (lib/engine/).
Search: Iterative deepening Negamax with Principal Variation Search (PVS), Aspiration Windows, Null-Move Pruning (NMP), Late Move Reductions (LMR), Razoring, Futility Pruning, Quiescence Search with SEE, and Transposition Table.
Evaluation: Tapered PeSTO piece-square tables, piece mobility, pawn structure, king safety, and passed-pawn evaluation.
Attribution: Search parameters, move-ordering scales, time management formulas, and tapered evaluation tables are adapted from Cheese 3.2 by Patrice Duhamel (cheesechess.net), distributed under the GNU General Public License v3.0.