[kwlug-disc] Single desktop of several devices -- does it exist?

[Mikalai Birukou]

I wonder if the following ever was created.

I put two devices next to each other, let's say pi's, each with a 
screen. Some settings latter, user can move mouse from one physical 
screen two another, and depending on the mouse location, keyboard events 
are sent to respective device.

Have you seen anything to support this user experience of seemingly 
going from one actual desktop machine to another, as if two screens are 
attached to one device (we don't move windows, as it assumes move of 
process from one device to another, yet).