I am very curious as to how this works. Is this just using RFB protocol? Would love to create something like this for the Raspberry Pi. I am guessing it needs Apple's blessing given that it connects via a lightning cable.
I did a bit of a dive on it a while back - it works via peertalk (https://github.com/rsms/peertalk), which in turn works by connecting to local sockets provided by `usbmuxd`.
I haven't tried to reverse it but it's definitely not plain RFB, performance is too good even on an iPad 3 (about the lowest CPU-to-pixels ratio of any iPad ever made). The latency is noticeable enough to be annoying for primary use but it's great for documentation, chat window, etc.
Really like Duet Display, though I wish the output quality was a bit higher (there's a quality slider in settings, but even on maximum there're lots of JPEG-like artefacts on the iPad display, especially around text).
I set it to the highest resolution it gave me (2xxx x 13xx, can't remember), and it is working great. Maybe it's on the notebook end? I also switched my NVIDIA driver to be used instead of the onboard Intel GPU for Duet.
