It's custom software, written by Mark Wherry at RCP. You can't get a copy.
For some rigs, we used an all-in-one touch PC. Dell Inspiron something-or-other (I don't remember the model at the moment). For other rigs, we used an Intel NUC with the touch display I linked to in an earlier post. Either way, it's a separate PC from the Cubase PC.
My memory is a little fuzzy, but I think that the software was able to send out actual key commands (over ethernet, which then hit a little "receiver" app on the main Cubase PC); or MIDI notes/CCs, in which case it just interacted with a Generic Remote in Cubase just like it would with Lemur/TouchOSC/etc.
The MIDI interfaces behind the touch screen/computer in the video above show half-rack MOTU units -- one of them is for the touch computer. MIDI just goes out of its MIDI interface and into the Cubase machine's MIDI interface over a MIDI cable. Super simple, easy, rock solid. We tried MIDI Over Lan and stuff like that but ultimately it was always a little funky or unreliable in some way, so eventually we just landed on reliable hardware and called it a day. It's easy to troubleshoot, too, thanks to the activity lights on the front of the units.
Even though you can't get the software from RCP, I've replicated and expanded upon this setup a few times now using MaxMSP in its place. In fact I'm building a template for a composer right now to replace a multi-tablet Lemur setup. The cool thing is that Max is able to do
far more than Mark's software ever could. That's no slight to Mark, he rocks, but Max is a whole different beast. I've come up with some cool MIDI-processing stuff, sequencers, the ability to control Philips Hue lights, etc, all sorts of fun stuff, all from the touch screen. It's awesome and IMO the best way to go nowadays.
That said, Mark's app had a real-deal implementation of Brian Eno's Oblique Strategies cards built into the app, and Max can't do that as far as I know