1) Traktor Pro 2 Over a decade on from its launch, Traktor Pro is pretty much the gold standard of digital DJing. While some of its rivals may do certain things better, no application can match Traktor for all-round flexibility and reliability. Between its excellent Sample Decks, Remix Decks and Loop Recorder, its high-quality effects and its impressive beat and key analysis algorithms, Traktor has pretty much everything a modern DJ is likely to need. 2) Ableton Live is something of an anomaly in this list, due to the fact that it’s not really a true DJ application - or at least it wasn’t originally imagined as such. Still, while it may have been first envisioned purely as a production tool, in the years since its inception Live has become a favourite of DJs across the world. Key to its popularity with DJs is the Session View - a brilliantly implemented and cleanly designed window for launching sync’d audio samples, MIDI clips and tracks. It’s this view, along with the intuitive way that Live handles retiming audio, that makes the DAW a fantastic tool for blurring the lines between DJing and live performance. With the added bonus of a heap of built-in instruments and effects, the ability to host plugins and an intuitive MIDI learn function, Live makes an unbeatable one-stop-shop for electronic musicians. What's more, you can choose from any number of controllers that are specifically designed to work with it. 3) Serato DJ Serato has come along way since spearheading the birth of digital vinyl DJing more than a decade ago. The company may have lost its grip as market leader to Native Instruments over the years, but constant development has meant that Serato’s DJ software is still up there with the best. With the launch of Serato DJ in 2013, the company finally combined the two disparate strands of its software - the digital vinyl-based Scratch Live and controller focussed Itch - into a single unified application. The app has developed nicely since then, offering plug 'n' play support for a range of controllers, expansion packs that enable you to add to the software's capabilities, and multiple views that can accomodate both 2- and 4-deck mixing. With the company now focussed on a single product, the future seems bright for Serato, and its software looks set to be a big part of the DJing landscape for years to come. 4) Mixvibes Cross Cross, from French developer Mixvibes, has undergone numerous updates over the past few years, resulting in an impressively extensive feature set. The application features a highly customisable interface that contains four decks, two eight-slot samplers, eight assignable cue points and 14 different effects. There’s support for a range of controllers (more than 80 at the last count) and digital vinyl systems, and it’s possible to import your music library directly from Pioneer rekordbox (which was itself developed by Mixvibes). There's SoundCloud integration, too, as well as the more predictable option to delve into your iTunes collection. There’s also a cool iOS remote control app available, which can act as a second screen for browsing tracks or a way to use the software decks remotely. Oh, and there are versions of Cross available for not only Windows and OS X, but also iOS and Android devices, making this a truly cross-platform offering. 5) Gibson Deckadance Now under Gibson's ownership (the company acquired the software from FL Studio developer Image-Line), Deckadance features some great beat grid editing tools, a highly customisable interface and a great Smart Knob function, which allows macro-style control over multiple effect parameters at once. The application also offers four-deck mixing, a 16-slot sample player and - possibly most impressively of all - can host external VST plugins, meaning that you can use your favourite third-party effects and instruments from within the software. On the downside, Image-Line’s list of preconfigured DJ controllers is a little behind that of some of its rivals, although it does feature an auto-learn function to allow relatively simple user-mapping, and there's a remote control app for iOS and Android devices.