Icecast, the project, is a collection of programs and libraries for streaming audio over the Internet. This includes:
icecast streams audio to listeners, and is compatible with Nullsoft’s Shoutcast.
From the README:
libshout is a library for communicating with and sending data to an icecast server. It handles the socket connection, the timing of the data, and prevents bad data from getting to the icecast server.
IceS is a program that sends audio data to an icecast server to broadcast to clients. IceS can either read audio data from disk, such as from Ogg Vorbis files, or sample live audio from a sound card and encode it on the fly.
Check your icecast configuration file for an element called <webroot>. This directory contains web stuff. In it, place a file called “status.xsl” that transforms an XML file containing stream data into a web page (either XHTML or HTML).
There are sample XSL stylesheets available in icecast/web/ in the CVS distribution of icecast.
In addition, the web directory can hold multiple status transforms, if you can’t decide which one you want.
We maintain a list of Icecast-compatible audio players at http://www.icecast.org/thirdparty.html.