NVMM is a full type-2 hypervisor solution for NetBSD on several architectures, Ironclad implements it as a cleaner, more lightweight version of something like Linux’s KVM. DragonFlyBSD hosts guides on using it here.
NVMM usually gets exposed in the way of a library, like libnvmm,
Ironclad only provides the building blocks of said library in the form of
syscalls. Ironclad distributions are invited to use
Gloire’s libnvmm, developed for
use with the Gloire distribution, but easily portable.