Xen Pushes 'Paravirtualization'
If you've been keeping tabs on virtualization news during the past several months, there's a good chance you've heard about Xen.
Xen, an open-source software project that began its life at the University of Cambridge, aims to virtualize operating system instances and to do so better than current options such as VMware Inc.'s products.
Rather than re-create a machine within which any operating system may run, Xen takes a "paravirtualization" tack-entire operating systems may run atop Xen, but their kernels must be modified to do so.
This approach means less operating system flexibility than you get from VMware; for example, Windows won't currently run on Xen. But the reduction in overhead incurred by running virtualized instances-as well as the project's free GNU GPL (General Public License)-has generated quite a bit of interest.