Virtual Machine Software

Virtual machine software either uses low-level capabilities offered by certain hardware environments or installs a complete hardware emulation layer using software to support multiple operating environments and the related stacks of applications, application development and deployment software, and system infrastructure software. Each of the client or server operating environments is allowed to believe that it controls the entire machine, but resources are actually allocated on the basis of rules established either at the time of configuration or dynamically by related management software. Thus, operating system software and applications that were previously incompatible could share the same machine. Representative vendors and products include the following:

• EMC (VMware ESX Server)
• IBM (VM)
• Jikes (Research Virtual Machine)
• Microsoft (Virtual PC 2004 and Virtual Server 2005)
• Xen virtual machine monitor (open source)