The WCCC is open to all types of computers including microprocessors, supercomputers, clusters, and dedicated chess hardware.
Due to the requirement to be present on-site, play on a physical board, and strict rules of originality, many strong programs refrain from participating in the ICGA events.
For the 2009 edition, the rules were changed to limit platforms to commodity hardware supporting at most eight cores,[2] thereby excluding supercomputers and large clusters.
The rules for the World Chess Software Championship (WCSC) state that competing programs must run on machines with identical hardware specifications.
[13] In the first three championships, the winners were dedicated chess computers, and then in 1984, Richard Lang's Psion program shared first place, running on an IBM PC under MS-DOS.