Synchronous Audio Router - Routes Windows application audio to and from your digital audio workstation software.
AudioBus - With Audiobus, the revolutionary new inter-app audio routing system, you can connect your...
Virtual Audio Cable - Ever wanted to record your speaker output? (loopback) This is for you.
Loopback by RogueAmoeba - Get all the power of a high-end studio mixing board, right inside your Mac!
LiveTrax - LiveTrax is an app by MasterMedia Productions through which musicians can control the playback of their favorite track during live performances by using simple controls.
SoundBunny - SoundBunny allows you to control the volume level for all open applications on your Mac.