Soundflower is a free, open-source Mac OS X application that allows users to route audio between applications on their computers. It enables users to send audio from one application to another, such as from iTunes to a recording program, or from a web browser to a media player. Soundflower works as a virtual audio device, allowing users to select it as a sound input or output within the preferences or settings of the application they wish to use. It is commonly used to record the audio output of a computer, to enable the streaming of audio between applications, or to record and edit audio from multiple applications at once.
Jack is too complicated. The sound flower was so simple, so buggy. How has no one made a good copy yet?