Vote for Citrix XenServer
Citrix XenServer, a member of the Citrix Delivery Center product family, is a way to virtualize servers and deliver dynamic data centers that are responsive to the ever-changing demands of business. Using Citrix XenServer, virtual server software companies can deploy high-performance virtual machines and manage them and their related storage and networking resources from a single management console.
The provisioning capabilities now available in Citrix XenServer virtualization software makes it a platform than can integrate the deployment and management of virtual and physical servers into a unified dynamic virtualized infrastructure - a flexible aggregated pool of computing and storage resources.