That sent me looking it up. It seems that NetBSD, as the only one, has a rump kernel, but it also looks like work on it stagnated around 10 years ago. That could be because the guy doing a thesis on them, moved on. There is quite some bitrot when following links. Do you know what happened? Were they a failure? Maybe they were surpassed by other OS architectures?
spragl|3 months ago