Sadly, this seems abandoned. Looks like the most advanced OS kernel in terms of features and hardware support outside of the big ones (Win/Lin/BSD/mac) is maybe Haiku? https://www.haiku-os.org/
Last commit seems to be from October.
That’s e.g. more active than Minix3.
Possibly Multics or the OSes IBM released into the Public Domain, depending on what kinds of hardware support you mean. But retrocomputing is probably outside of what you have in mind.
Yeah, I meant “daily driver” replacement potential.
Besides Haiku, maybe AROS, Genode (Sculpt), Plan9front, Minix3, ReactOS, Freedos, HelenOS.
Each currently suiting different levels of “daily driver”.
For instance, it’s very possible for me to use Sculpt as daily driver as long as I ran a Linux VM under it for some tasks like web browsing or ssh-ing to jump hosts.
That’s cheating! :D
Not as much as using an actual Linux from a serial terminal through freedos to work.
Why ssh? It shouldn’t be too bad to port openssh. I did it for fuchsia when we were missing a lot.
Yes, that’s apparently already working, both server and client.
It’s been a while since my comment, so I don’t remember my intent, but I might have meant “cheating by Linux VM” and “cheating by ssh” as separate options.
Source code seems to live here: https://github.com/osfree-project/osfree/