A favorite chess variant of mine that I've played on the Zillions of Games
software is called Alekhine Chess. Of all the chess variants that I played
on Zillions it's my favorite. You can read about it here
http://www.zillions-of-games.com/cgi-bin/zilligames/submissions.cgi?do=show;id=39
It has a non-standard board size of 8 x 14 squares and 3 non-standard
pieces. The rook/knight, bishop/knight and a queen/knight. All the other
chess pieces are used. If you wanted to play it on a standard 8 x 8 board
you could play a variant of this variant by just using one rook, knight,
bishop, bishop/knight, rook/knight and queen/knight and that way get in the
3 different pieces on a standard board.
I recommend Alekhine Chess to anyone looking for an interesting chess
variant. May not be easy to find someone to play it with though you could
play it on the Zillions of Games software. Zillions came out years ago and
am not sure if it is compatible with Vista or Windows 7 but it is with XP
and earlier versions of Windows. Anyone looking for a way to play chess
variants against a computer might want to check out Zillions of games.