This document discusses virtualization technologies supported by OpenStack Nova. It mentions that Nova uses a virtualization controller (IaaS) and supports para-virtualization through KVM, XenServer, and Hyper-V. It also discusses the Linux Container (LXC) operating system that Nova is built on using Python. Key virtualization backends supported include Libvirt, XenServer, VMWare, Hyper-V, bare metal, Docker, Xen with Libvirt and LXC with Libvirt. The document also mentions Nova provides support for various virtualization technologies through Libvirt like KVM, Xen, LXC, OpenVZ, UML, VirtualBox, VMware, Hyper-V, PowerVM, Parallels, and B