[samatman]

It's an actual kernel the same way a virtual machine is an actual machine.

To unpack that: a virtual machine could be a real machine, it just happens to instead by a software-hosted emulation thereof. There's a hardware JVM in your SIM card, for an example.

arvo (the kernel) is the same deal: there's nothing stopping someone from implementing the syscalls it uses (used to be seven of them IIRC), writing some drivers, and running it on bare metal.

But that's a lot of work, and the Unix-hosted virtual kernel works well enough. The whole thing may be fairly compared with inferno, which is a hosted plan9 which runs on a VM.