Mixxx - The most powerful free DJ software in the world.
Knowthelist - Knowthelist - the awesome party music player Easy to use for all party guests
VirtualDJ - Virtual DJ Software - MP3 and Video mix software for DJs
Song Director - Song Director is a program that plays and keeps track of all your music files.
Traktor Pro - Flagship DJ software with four decks and a stunning range of creative features for maximum freedom in DJing.
MixTape - Home of MixTape, an OSX application for creating beat matched mixes with simple export to the web or iTunes.