It’s not an emulation or simulation of the TB-303 synth. It is an homage to TB-303, and other hardware synths. It’s a complete different beast, but it has the same functionality. It growls and barks with fierce resonance. SquareAcid is a singular squeal, squelch, and bleep machine. It comes as a stand alone app with Audiobus and Ableton Link. It also comes with an AUv3 audio unit plug-in. Features: Audiobus Ableton Link IAA AUv3