Oracle GNU/Linux 5.2 and Oracle Xen VM Server 2.1.2 ISOs are now available for download from:
http://www.oracle.com/virtualization
and you can get some Oracle Xen VM templates from
provide a variety of downloads and howto’s to facilitate use of the Xen Virtual Machine Monitor.
Jailtime.org have Linux distributions that can run as Xen guests out of the box, obviating the need to create your own custom filesystems. The filesystems on this site have already been tweaked to deal with Xen’s idiosyncracies, and are also designed to be lightweight and minimally divergent from the original distribution.
The Google App Engine JumpBox gives you a drop in place system for doing Google App Engine development that’s contained in an isolated environment within a virtual machine.
It runs exactly the same on GNU/Linux, Mac and other OS’s and gives you a development environment that lets you take advantage of great virtualization features like snapshots. It will run from a single download on Parallels Desktop, VMWare, Virtual Iron, Xen Open Source in fully virtualized mode and others.
according to http://www.novell.com/connectionmagazine the latest version (10.3) of openSUSE now includes VirtualBox & Xen virtualisation platforms
There is an OpenVZ live-CD VZ VM server with VZ VM guests (based on CentOS or KNOPPIX) that you can download from http://wiki.openvz.org/Download_live_CD
And there is a quick start guide to read at http://wiki.openvz.org/Getting_started_with_OpenVZ_live_CD