I know of many things!
Your question is not clear, however. What do you mean by 'create a chess variant'? A program that randomly cranks out a set of rules (e.g. for how large the board is, which pieces you have, how these are allowed to move, which square they start on, and what you would have to do to win).
As Pritchard wrote in his book about Chess variants: "It only takes 10 sec to create a new Chess variant, and unfortunately some people do!". So a computer could probably do (even more unfortunately) 1000/sec!
Anyone know of anything?