Icecast is a streaming media server which currently supports Ogg Vorbis and MP3 audio streams. It can be used to create an Internet radio station or a privately running jukebox and many things in between. It is very versatile in that new formats can be added relatively easily, and it supports open standards for communication and interaction.
The streamTranscoder is a multi-platform utility which can be used to transcode media streams from one format to another, and from one server type to another. It will read in streams of type MP3 and Vorbis from most servers (Icecast, Icecast2, Shoutcast), convert it into various formats, and send to various streaming servers.