Nullsoft's Free Winamp-based distributed streaming audio system. Anyone can broadcast music through this streaming technology. Site features online documentation, downloads, news, and station showcase.
Open source broadcast system based on the MP3 streaming audio format. Information on downloading the server application and participating in its development, as well as a directory of current icecast broadcasts.
Open source server engine with the ability to mix, encode, and stream sound dynamically. Can optionally support Ogg Vorbis input, and can send streaming sound to an IceCast server. Site describes the features with screenshots.