UCI chess engine
Portable UCI- and XBoard-compatible chess engines.
Chess program for windows and linux
Chess training program playing gambits
Tool for chess teachers to create PDF files with chess diagrams in it
Batch tools for creating Polyglot books and PGN-based statistics.
NetChess to play between two players over net or internet
a UCI chess engine
Python chess engine
A console/ncurses chess engine frontend and PGN editor.
EXCEL VBA chess engine with chess board
Extensive Java chess database libraries.
Java Chess Engine
icsdrone is an interface between a chess server and a chess engine
The world's smallest chess playing program just got smaller!
A weak open source java chess engine
Chess engine, currently in development