Just the help section of http://cowplay.com but it's not complete
the inventor is an active member there (chessteacher)

Fencer: No, they said to inventor that he shouldn't choose a name like super,mega,meta,...

it's setup is like chess, every piece inherite the power of the same color,same file pieces power

on the first move it's possible to play pc2xh7 and now this pawn is also a rook(not a bishop anymore)
because of that there is a second variant of it with rook pawns on a3,h3,a6,h6
it's a very dynamic variant, every piece has the chance to be a queen, or even an amazon so matrial is less important.
object is checkmate, no en passant or castling

There is a variant on cowplay.com site which is called MetaChess(2).
It's a nice variant, and would be great if implemented here.