GNU Chess
 GNU Chess 5.0.7 on WinBoard 4.2.7 | |
| Developer(s) | The GNU Chess Team |
|---|---|
| Stable release | |
| Repository | |
| Operating system | Unix, GP2X, Windows |
| Type | Computer chess |
| License | GPL |
| Website | GNU Chess |
GNU Chess is a computer program for playing chess. GNU Chess is one of the oldest computer chess programs for Unix-based computers and has been ported to several other platforms. The GNU Chess project is one of the older parts of the GNU package of software, having started in 1984. The first version of GNU Chess was written by Stuart Cracraft. [1] All subsequent versions before version 5 were written by John Stanback.
GNU Chess is free software, licensed under the terms of the GNU General Public License, and is maintained by collaborating developers. It is often used in conjunction with a GUI program such as XBoard.
In 1998–1999 GNU Chess underwent a transition to version 5. Version 5 was essentially a complete rewrite from scratch of GNU Chess to eliminate spaghetti code and replace antiquated data structures with more advanced computer chess implementation techniques. These included bitboards, a search algorithm called Principal Variation Search (PVS) (a variation by Professor Tony Marsland of alpha-beta minimax), and full end-leaf evaluation. The primary author of version 5 was Chua Kong-Sian. [2]
It uses a number of other techniques to improve its performance, such as an opening book (generated by studying master games) to help it start well and hash tables storing previously-analyzed positions to prevent wasting time re-analyzing already analyzed positions.
