P2P-Radio is a tool to broadcast video and audio streams via a peer-to-peer listener network It can distribute audio streams in the MP3 and Ogg Vorbis formats and video streams in the NSV format.

"DarkIce is a live audio streamer. It records audio from an audio interface (e.g. sound card), encodes it and sends it to a streaming server." It can encode to mp3, mp2, Ogg Vorbis and aac and can send the the resulting stream to ShoutCast, IceCast and Darwin streaming servers. GNU/GPL.

The Multiple Streaming Engine looks like a very capable open-source tool for mixing/encoding your streaming broadcasts. "MuSE is an application for the mixing, encoding, and network streaming of sound: it can mix up to 6 encoded audio bitstreams (from files or network, mp3 or ogg) plus a souncard input signal, the resulting stream can be played locally on the sound card and/or encoded at different bitrates, recorded to harddisk and/or streamed to the net. When sent to a server, the resulting audio can be listened thru the net by a vast number of players available on different operating systems."

There are various Linux versions available as well as one for Mac OSX but at time of writing there is no Windows version. You can download a dyne:bolic Linux installation 'live CD' which boots straight off the disk and has MuSE pre-installed, however.