This article is from the GNU Chess and XBoard FAQ, by Tim Mann firstname.lastname@example.org with numerous contributions by others.
Crafty is a freely-available chess program written by Bob Hyatt. Bob is
the main author of the well-known chess program Cray Blitz. Crafty is
already a much better chess program than GNU Chess on many dimensions:
it plays better, the code is commented and readable, and the author is
actively working on improvements.
You can download Crafty from ftp://ftp.cis.uab.edu/pub/hyatt/ . Start by
getting the read.me file and reading it. Among other things, this file
contains instructions on how to install Crafty as a command-line
application on your machine.
There is a Crafty mailing list hosted at http://www.jpunix.com/ . To
subscribe, send email to email@example.com.