Xen is a virtual machine monitor for x86 hardware (runs only on
i686-class CPUs), which supports running multiple guests operating
systems on a single machine.  Guest OSes (also called "domains")
require a modified kernel which supports Xen hypercalls in replacement
to access to the physical hardware.  At boot, the xen kernel is loaded
(via grub) along with the guest kernel for the first domain (called
domain0).  domain0 has privileges to access the physical hardware (PCI
and ISA devices), administrate other domains and provide virtual
devices (disks and network) to other domains.

This package contains the Xen3 kernel itself.