what kind of kernel is this?

[Craze Frog]

Using software protection was a very big policy decision.

Using hardware protection is a very big policy decision. That means there are no microkernels.

EDIT: grammar

Software isolation can be implemented on top of hardware isolation, but not vice versa. If you don't understand that, then I can't explain it any better.

[Colonel Kernel]

Separation of mechanism and policy is much easier in a microkernel architecture, but it is not a requirement. Mach and QNX are both microkernel architectures and both have plenty of policy (scheduler, memory management) in the kernel.

Singularity can use hardware isolation as well as software isolation. My point was that flipping the switch to enable hardware isolation does not suddenly make it a microkernel.