Mixxx - The most powerful free DJ software in the world.
MixTape - Home of MixTape, an OSX application for creating beat matched mixes with simple export to the web or iTunes.
Serato DJ - Serato DJ is award winning, digital DJing software used by professionals across the globe.
Song Director - Song Director is a program that plays and keeps track of all your music files.
Djay - djay gives you instant access to all your existing tracks and playlists from iTunes.
ServeStream - ServeStream is an open-source application that is intended for HTTP media player streaming, and the media server browser comes with the alluring support for custom online radio and Shoutcast streams.