you might wanna try [fiddle~] as well. not exactly the same (specially if you're only interested in amplitude control) but pretty neat.
r
% evol~~~~~~ http://www.mego.at/evol.html
% alku~~~~~~ http://personal.ilimit.es/principio
% imbécil~~~ http://imbecil.net
% foofoofoo~ http://openserver.cccb.org/~foofoofoo/index.html