AudioBus - With Audiobus, the revolutionary new inter-app audio routing system, you can connect your...
Volume2 - Volume2 is an advanced Windows audio mixer, a complete replacement for the standard Volume Control.
Loopback by RogueAmoeba - Get all the power of a high-end studio mixing board, right inside your Mac!
EarTrumpet - Volume Control for Windows
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.
Audio Sliders - Volume Control replacement that is five times smaller than its Windows counterpart.