The basic set of audio signal-handling libraries and drivers bundled with Apple’s OSX operating system, which provides a standard interface to audio interface hardware connected to a Macintosh. This software set is intended to replace earlier standards like ASIO and device-specific drivers with a universal software interface that will (in theory) work with all types of audio interface connected to an Apple computer. Not to be confused with Audio Units, also found in OSX but which serves a different purpose.