As virtualization of server OSes becomes more common, both VMware, which remains the leader in the virtualization software market, and other vendors are expanding their offerings to tackle the problem of virtualization desktops and applications that run on desktop computers.

Even though VMware remains the leader in virtualization across the board, the company has had a bumpy year in which it's faced its stiffest competition to date. Vendors such as Microsoft are building virtualization directly into their server OSes and also branching out into desktop and application virtualization. And in July, the company had a major executive shake-up, with CEO Diane Greene leaving suddenly to be replaced by former Microsoft executive Paul Maritz.