Xen is a virtual machine monitor

This package contains the Xen tools and management daemons needed
to run virtual machines on x86, x86_64, and ia64 systems.
Information on how to use Xen can be found at the Xen project pages.

The Xen system also requires the Xen hypervisor and domain-0
kernel, which can be found in the kernel-xen* package.

Virtualization can be used to run multiple operating systems on one
physical system, for purposes of hardware consolidation, hardware
abstraction, or to test untrusted applications in a sandboxed
environment.