Microsoft Hyper-V Server 2008
Microsoft has just released Microsoft Hyper-V Server 2008.
Note that this is not Microsoft Windows Server 2008 with Hyper-V. This is something different.
It " is a stand-alone hypervisor-based server virtualization product that allows customers to virtualize workloads onto a single physical server"
"It contains just the Windows hypervisor and other kernel components to support virtualization".