Comment by seec

Full VMs make much more sense indeed, because they allow you to run fundamentally different OS while still keeping the host mostly the same. And they basically show that with the FreeBSD addition.

The syscall way is just a form of emulation that you have to contain and it becomes a pain to keep up to date. VMs will use more ressource but at least they are disposable and only require a good virtualization layer on the host.

Funnily enough, with time, Microsoft might be able to run all the OSs inside their own OS. Of course, that won't happen for something like macOS but that would be hilarious.