I believe you can use the CDJ900's as HID MIDI to control the Traktor Software for searching files with rotary knob and it will read the players however you have to have at least one of the CDJ900's if not both plugged directly to the usb of your laptop, kinda of a downer for us MAC guys with only 2 USB ports. You can try one in a hub but at least one has to be plugged in directly. as for the rest of the software functional unless you have an interface it'll all have to be run on the laptop only cause you can't map a DJM800. but i don't believe you'll have to have an interface just to run the CDJ900's with Traktor. Here's a better youtube link that may help http://www.youtube.com/watch?v=QzxDX1c2qIM