Many thanks to Chris Hall for sharing what he is up to (it's not too late to send us yours).
There are eight computers in seven cases connected to four screens, four keyboards and four mice via various switch boxes.
LH screen: A RISCube running Windows 7 and VRPC Adjust. This has a SCSI-connected A3 page feed scanner and various networked items: a Brother HL-1550DN laser printer, a OKI C831 A3 laser printer and a 12TB NAS. (An earlier RISCube model is hidden behind the LH monitor)
Mid left screen: An ARMX6 - I use this for e-mail and development.
Mid right screen: A TiX Duet running Windows 10 and VRPC Adjust.
RH screen: A 4te computer in the blue case.
Not being displayed is a 4te2 computer, a PiHard and a kit built Titanium.
I have to think hard which buttons to press to bring up different displays/ connect a keyboard to a different computer. When I set several off doing different tasks I have to think carefully before pressing escape!
I prefer a hardware solution to a software solution so I haven't experimented with VNC yet.