See also: Xiph.Org | Ogg Vorbis | Ogg
Home Page: http://www.icecast.org
From the Homepage:
Icecast is an audio broadcasting system that streams music in the Ogg Vorbis format, and is available under the terms of the GNU GPL.
For IceCast related questions, search or post questions to this unofficial IceCast forum (hosted by Nabble).