CRN | Microsoft Has New Take On Virtualization "Microsoft promises to ease server application migration and simplify test environments with the forthcoming release of Virtual Server 2005, an application that virtualizes the Windows 2003 Server operating system. Virtual Server 2005 allows administrators to concurrently run multiple operating systems or multiple instances of Windows 2003 Server.
While server virtualization is nothing new, Microsoft's approach is different from competitors such as VMware. Virtual Server 2005 creates its virtual machines on top of Windows 2003 Server, compared with products that perform virtualization at the hardware level.
Both styles of virtualization have advantages and disadvantages. Hardware-level virtualization provides an operating system-agnostic approach, but often lacks tight integration with host operating systems. On the other hand, Microsoft's approach requires Windows 2003 Server, but Virtual Server 2005 can leverage the management and performance tools included in Windows 2003 Server, making virtualization almost transparent."