Microsoft Virtual Server 2005:
Microsoft Virtual Server 2005 allows system administrators to consolidate separate hardware servers on to a single server running Microsoft Windows Server 2003 as the host operating system.
Each of the hosted servers runs in its own separate and isolated virtual machine environment. This allows the administrator to easily manage, provide for, and maintain large numbers of servers, and reduces the need to run multiple hardware servers in order to utilize various server products and operating systems.
Another advantage of the virtual machine environment is in test and disaster recovery. Each virtual machine session running under Virtual Server is maintained as a file, which is easily archived or transferred to another hardware server in the event of a failure. New server and system configurations can be deployed and tested in parallel with the existing system without requiring costly downtime during the rollout phase.   _{Your Comment}