Xen is making progress in getting to the server world, with a recent addition into Red Hat Enterprise Linux. Part of the most recent RHEL beta, it is currently supported for standard x86 and 64-bit x86 architectures, and Red Hat is looking for active feedback on how well Xen works as a virtualization suite. They are including many other bonuses aside from Xen, but it is definitely the most notable for them. Look out, Vmware and Microsoft. Xen is on its way.