I don't think XNU is a microkernel in any real sense. Certainly not in the sense that the Minix kernel is or was. The filesystem, device drivers, IPC, network

I don't think XNU is a microkernel in any real sense. Certainly not in the sense that the Minix kernel is or was. The filesystem, device drivers, IPC, network stack, etc is all in kernel space. It's true that it's built around the Mach microkernel, but like most systems that built around it, Mach is just a core layer in the kernel onion, rather than a microkernel in and of itself with the other major components implemented as user-space servers.