) is a hypervisor using a microkernel design, providing services that allow multiple computer operating systems to execute on the same computer hardware concurrently.It was developed by the University of Cambridge and is now being developed by the Linux Foundation with support from Intel.
This is known as hardware-assisted virtualization, however in Xen this is known as hardware virtual machine (HVM).
HVM extensions provide additional execution modes, with an explicit distinction between the most-privileged modes used by the hypervisor with access to the real hardware (called "root mode" in x86) and the less-privileged modes used by guest kernels and applications with "hardware" accesses under complete control of the hypervisor (in x86, known as "non-root mode"; both root and non-root mode have Rings 0–3).
A new community website was launched at Makes it possible to use a dom0 Linux kernel, which has been implemented by using PVOps.
A Linux kernel of version 2.6.31 has been modified for this purpose, because the official Linux kernel actually does not support the usage as dom0 kernel (date July 2010).
Xen Project is currently available for the IA-32, x86-64 and ARM instruction sets.