Do they exist? If so, where can I find them? Also, will they work on Garageband? Ableton has been irritating me.
There are definitely free VSTs; I've posted a link to a good list of free music software before; search for it on SoundTempest or search the forums here. As for what Garage Band can handle, I don't know. There certainly are Mac-compatible plugin formats, and I believe that VSTs are one of them, but I'm not certain, and GarageBand doesn't necessarily support every possible plugin format allowed on the Mac. Also, keep in mind that you can't use a Windows plugin under OSX.