Lichess - Free online chess game server focused on real time gameplay and ease of use. (Code) Lc0 - UCI-compliant chess engine designed to play chess via neural network, specifically those of the LeelaChessZero project. (Web) Chess With Friends - Play chess and video chat with your friends at the same time, no login required. (HN) go-chess - Go library which provides common chess utilities such as move generation, turn management, checkmate detection, PGN encoding, and others. OpeningRepertoire - Command line tool that generates opening repertoires from chess games in PGN format. (HN) python-chess - Pure Python chess library with move generation, move validation and support for common formats. gym-chess - Simple chess environment for openai/gym. Sjeng - Chess-and-variants playing program. lichess puzzler - Use stockfish and database.lichess.org to produce puzzle candidates. ChessBase - Chess database with eight million games. Openings, players, tournaments. Theory of Chess - Open-source cheat sheet for most common openings to teach myself what can transpose into what. (Reddit) chessops - Chess and chess variant rules and operations in TypeScript. fishnet - Distributed Stockfish analysis for lichess.org. shakmaty - Rust library for chess move generation. chess-pipeline - Pulling games from the Lichess API into a PostgreSQL database for data analysis. chess-engine - Pure Rust, dependency-free chess engine that doesn't require a runtime. ChessCraft - Never play the same game of chess again. Listudy - Improve you chess game with spaced repetition. OpeningTree - Consolidated view of all your chess games from chess.com, lichess, grandmaster games or custom pgn. (Code) scalachess - Chess API written in Scala. Immutable and free of side effects. daochess - Testing governance mechanisms via chess. OTB Chess - Place where people can find opponents to play Chess Over the Board. Sunfish - Python Chess Engine in 111 lines of code. (Wiki) FastChess - Predicts the best chess move with 27.5% accuracy by a single matrix multiplication. Chess Position Ranking - Software suite for ranking chess positions and accurately estimating the number of legal chess positions. node-chess - Algebraic notation driven chess engine that can validate board position and produce a list of viable moves (notated). Coronate - Swiss-style chess tournament management app. (Web) poirebot - Chess engine and bot written in Rust. Blunder - UCI compatible chess engine written in Go. Drofa - UCI chess engine written in C++. Halogen Chess engine - Written in c++. Implements Null-move pruning, Late move reductions, Quiessence search and a Transposition table that uses Zobrist Hashing.