sonic surrounds

MusicKit is an object-oriented software system for building music, sound, signal processing, and MIDI applications. It has been used in such diverse commercial applications as music sequencers, computer games, and document processors. Professors and students in academia have used the MusicKit in a host of areas, including music performance, scientific experiments, computer-aided instruction, and physical modeling. The MusicKit was the first to unify the MIDI and Music V paradigms, thus combining interaction with generality (Music V, written by Max Mathews and others at Bell Labs four decades ago, was the first widely available “computer music compiler”).

So it’s not particularly new, but has been ported to Mac OS X by Leigh Smith and the sourceforge repository holds some useful recent Core Audio code for learning from.

Acousmodules offer a large variety of tools for multichannel composition.

This page on their site lists the features of a large range of multitrack and plugin host software packages that may be useful in multichannel composition from mono, stereo, 5.1 to many more channels. An interesting survey since I have recently become interested in exploring currently available audio processing environments that will support 5.1 and greater multichannel sound composition.