Open-source KVM software
Do you mean like use them all at once with single keyboard and mouse? You could use mix of Barrier (https://github.com/debauchee/barrier) and at the same time universal control (for the Mac and iPad). Hope this helps…
NOTE: The number of mentions on this list indicates mentions on common posts plus user suggested alternatives. Hence, a higher number means a more popular project.
KVM with both DPI and HDMI?
1 project | reddit.com/r/workfromhome | 15 Aug 2022
Switched to Linux at work... 2 Months later
1 project | reddit.com/r/linux | 14 Aug 2022
Magnetic USB cables to hotswap one keyboard between two PCs - 3D printed "KVM switch"
2 projects | reddit.com/r/MechanicalKeyboards | 13 Aug 2022
I have 2 computers and 2 monitors
1 project | reddit.com/r/buildapc | 12 Aug 2022
Keyboard and Mouse to be used with two laptops at once!
1 project | reddit.com/r/ITdept | 11 Aug 2022