The New York Times writes:
VMware, a young Silicon Valley company, is the early leader in a fast-growing market for what is called virtual-machine software. And that puts it on a collision course with Microsoft, the industrys Goliath.
A virtual machine essentially mimics a computer so that several copies of an operating system say, Windows or Linux or both can run on one physical machine. It allows computing chores to be done on fewer computers, using less electricity and taking up less space, promising a way to control costs at corporate data centers straining to keep up with the ever-increasing demands of the Internet age.