[jevogel]

It already exists commercially. Search for boundless or borderless or roaming KM switch.

[vidarh]

Having searched for that, most options I find are either ridiculously expensive, and/or poorly documented or limited. Any suggestion for good ones?

Frankly I'd be far more inclined to pay the "ridiculously expensive" prices for one that is well documented and open, and where the firmware is easily modifiable.

[mtlynch]

I make one that I put a lot of effort into documenting:

https://github.com/tiny-pilot/tinypilot

It's pretty easy to extend since it's just Python and vanilla HTML/JS/CSS, so there's not much of a toolchain to install.

You can buy it pre-made for $399 or make a DIY one for under $100.

https://tinypilotkvm.com/blog/build-a-kvm-over-ip-under-100

[vidarh]

This seems to be a KVM switch, not a boundless/roaming KM switch?

Note no "V"; it's to have the mouse seamlessly move from one desktop to the other when the machines are each connected to their own screen. Browser-based is also a non-starter for that use.

I'll definitely have a look if/when I need a KVM over IP switch, though.

[mtlynch]

Ah, yes. My mistake.