Hyatt is co-author of the computer chess program Crafty and the co-author of Cray Blitz, a two-time winner of the World Computer Chess Championships. He has been actively involved in computer chess since he first started to program a computer to play chess in 1968. These efforts have been supported by various computer vendors such as Univac (1978), Cray Research (1980-1994), and more recently AMD via their developer's lab. Crafty is freely available both in executable form (from many different web sites) and in source form (from Hyatt's home page). Crafty presently participates in many computer chess tournaments (and an occasional human chess tournament). An old version of the source of Cray Blitz is also available on the internet for those interested in seeing what computer chess looked like in the late 1980s.