Not _technically_ a hypervisor since these are Linux (system) containers and use the same cgroup magic under the hood as docker/containerd. But this is definitely neat. I've found Incus quite handy for development environments, and a good compliment to docker.
You can also start QEMU/KVM powered VMs with Incus, I assume that's also possible with IncusOS?
The Incus server inside IncusOS is the same software. The difference is as little userspace as possible alongside it (not even busybox).