Mixxx is described as 'The most powerful free DJ software in the world' and is a very popular app in the Audio & Music category. There are more than 25 alternatives to Mixxx for a variety of platforms, including Mac, Windows, Linux, iPhone and iPad. The best alternative is VirtualDJ, which is free. Other great apps like Mixxx are Traktor Pro (Paid), Giada (Free, Open Source), Luppp (Free, Open Source) and Pacemaker Editor (Free).
Internet DJ Console is a project started in March 2005 to provide a powerful yet easy to use source-client for individuals interested in streaming live radio shows over the Internet using Shoutcast or Icecast servers.
Torq 2.0 takes you beyond beat matching and into the future of DJ performance and real-time production. Don't just spin tracks - reinvent them. Take advantage of all four decks to create unique, complex, and dynamic mixes.
xwax is open-source vinyl emulation software for Linux. It allows DJs and turntablists to playback digital audio files (MP3, Ogg Vorbis, FLAC, AAC and more), controlled using a normal pair of turntables via timecoded vinyls.
TerminatorX is a realtime audio synthesizer. This software allows scratching audio data (wav,ogg,mp3, etc.) the way hiphop-DJs scratch on vinyl records. It features multiple turntables, realtime LADSPA effects, a sequencer and MIDI interface.