From LQWiki

The popular game of chess under *NIX is usually split into two separate parts, the frontend, and the backend. The frontend is the part you see. The backend is the chess engine or AI, and determines what moves to make when asked by the frontend.

Front Ends

• PyChess
• glChess
• Knights
• XBoard

Back Ends

• Amundsen
• Crafty
• Diablo
• Faile
• Fruit
• Glaurung
• GNUChess
• Phalanx
• Sjeng