DJ software comes in all shapes and sizes - some good, some bad. Some aim to reinvent DJing for the digital age, whereas others - algoriddim's djay for Mac in particular have stayed pretty faithful to the conventional roots of 2 turntables and a mixer. And they've learned a few things over the last couple of years, and importantly listened to users to bring djay up to version 4. And yes, you might recognise the camera work. That's 5 days in the dark right there.