Xen is an open-source hypervisor developed at the University of Cambridge. Xen runs a single “host” domain known as Dom0 with certain management priviliges, from which it manages the “guest” virtual machines (VMs) known as “DomU”. Dom0 uses the Linux kernel (more precisely, a xen-ified version of it) to manage access to the underlying hardware in much the same way that the Linux operating system‘s kernel manages access between hardware and software.
Xen is able to make use of a particular type of virtualisation called paravirtualisation, in which the guest operating system is somewhat aware of the fact that it is being virtualised, which allows for faster access to the underlying hardware.
Commercial versions of Xen, such as Citrix Xenserver, are also available.
Last updated: 4 September 2017