Chenard is a free and open source chess program written in C++. The code is very mature and well-tested (started in 1993). It is not the strongest AI out there, but it will provide a serious challenge for most people.

Chenard supports the following platforms:

• Windows 32-bit and 64-bit (GUI and command-line).
• ChenServer TCP server (provides chess logic outside of C/C++).
• WinBoard plug-in engine.
• Linux xboard plug-in engine.
• Linux command-line.
• Mac OS command-line.
• TTY version for use on serial teletype machines.

For more information, see the Chenard home page.