Soundflower is a free and easy to use  Mac OS X system extension that allows applications to pass audio to other applications.

Soundflower is easy to use, it simply presents itself as an audio device, allowing any audio application to send and receive audio with no other support needed.

Soundflower is a virtual audio device that provides an easy and simple way for Max/MSP and other applications to send and receive audio to and from any other application. 

Running with very low latency and cpu usage, Soundflower allows each client application to use its usual buffer size.

What's New in This Release: [ read full changelog ]

· Added 64-bit support for Intel architectures (merge from Rogue Amoeba sources).