Palo Alto-based VMware said today that Diane Greene, the firm's President and CEO, has left the company. According to VMware, Paul Maritz has been named President and CEO of the firm, and joined the board of directors. Greene was a founder of the company, and a major force behind the company. No reason for the change was given, however VMware said that it expects revenues for the full year of 2008 to be modely below previous guidance. Maritz was President of EMC's Cloud Divison, and previously was founder of Pi Corporation, which EMC acquired in February.