Apophysis. It can be found on sourceforge if you plug Apophysis into the software search criteria.
I think it's sourceforge.net/project/apophysis, but I'm not entirely sure on that address. The current version is 2.04beta. I've been using Apo since late 2004, I believe. It's come a ways since then with a lot more interesting variations, and now the "final transform."
It's also freeware so it won't cost you a dime to get.