acid type program for mac?

is there a program for mac that will time stretch and keep pitch easily like acid. or does acid have a mac version.

That would be "Live". It does all that, and a lot more to boot.

Don't rule out Soundtrack Pro from Apple. I use it every day.

Really, if you're talking mostly about stretching percussion loops, maybe a program that works with REX files will do what you need. Look at Stylus RMX, Reason.... And all the DAW's can import them, now. Or do you need more than that?