GNU Chess

GNU Chess is a free softwarechess engine and command-line interfacechessboard. The goal of GNU Chess is to serve as a basis for research, and as such it has been used in numerous contexts.

GNU Chess is free software, licensed under the terms of the GNU General Public License version 3 or any later version, and is maintained by collaborating developers. As one of the earliest computer chess programs with full source code available, it is one of the oldest for Unix-based systems and has since been ported to many other platforms.