DJing software is often expensive but Mixxx breaks the mold as an excellent, open source and free DJing app that's incredibly accomplished.
Mixxx features everything you'd expect in a commercial package including MIDI controller support and a mixing engine with recording vinyl control. When you start Mixxx, it automatically scans your music library for audio files which is a bit annoying because you don't get any choice over it. You have to wait for this to finish before you can get stuck into Mixxx but it's worth the wait.
Mixxx is complete but not too complicated for the aspiring DJ. There's plenty of documentation for those that do get stuck but there's nothing more to it than browsing to your music library and selecting two songs to use - one for the left and right decks. The crossfader is in the middle of the deck for manual control but you can let Mixxx take control with it's auto-syncing option. This tries to measure the BPM's of each song and can result in some weird results but it's impressive.
For professionals, you can add external devices such as CD players and vinyl decks. To use the rest of the controls you'll have to know something about mixing decks and how they work.
Mixxx is an excellent simple mixing decks for anyone that's having a party or wants to get going as a DJ - best of all it's completely free.
