Actually, I&#x27;ve asked my question after trying to do some basic reading on my own, but it only deepened my confusion, unfortunately. I vaguely remembered that &quot;rump kernels&quot; seemed to mean &quot;assume we&#x27;re on Xen&#x2F;KVM&#x2F;... and make use of that&quot;, or a notion of &quot;library kernels&quot; -- one of those two, though not 100% sure which one (or both?). But then from some NetBSD docs&#x2F;wikis&#x2F;... it started to look to me like they&#x27;re adding another term &quot;anykernel&quot; here and there, and then naming with that some microkernel-like stuff, like mounting stuff in userspace, but then not sure why naming the option as &quot;rump&quot;, etc -- and all of that made me more and more confused, instead of less. And that&#x27;s what made me ask here.