Audio

Mac OSX MIDI Developers Resource
Caters to developers of MIDI applications under Mac OSX. Online Apple documentation available as well as custom examples.
http://xmidi.com/

MacMusic
Making music with a Macintosh: Resources, more than 1200 searchable links, downloads, updates, drivers, classified ads, mailing-list, articles, info. All you need to make music with your Macintosh, free and available in English and French.
http://www.macmusic.org/

MacRocks
A source for information about making music on Macintosh computers. Features Mac audio news, hardware and software reviews.
http://www.macrocks.com/