Xen is a virtualization technology for IA-32, x86-64 and ARM architectures.
Xen is an Open Source "type-1" hypervisor that provides high-performance virtualization of IA-32, x86-64 and ARM architectures.
The homepage for the project is: http://www.xenproject.org/
One of the Xen project goals is to take advantage of new developments in system architectures to demonstrate their advantages and serve as the reference hypervisor of choice.
Development activity takes place on the xen-devel@xen.org public mailing list, and questions from users about deploying Xen are served by the xen-users@xen.org public mailing list.
Xen originated from the Cambridge University Computer Laboratory and was first described in the research paper "Xen and the Art of Virtualization" at SOSP in 2003. This introduced "paravirtualization" as the concept of modifying the kernel of the guest operating system to be aware of the hypervisor, and so change its behaviour to optimize performance, whilst still allowing guest applications to run unmodified.
Just as Linux distributions provide an environment and packaged version of the Linux kernel, similarly Xen is packaged and made available commerically by multiple vendors, including Citrix, Oracle, SuSE (or their current owner), and RedHat.
