Microsoft has formally opened the new international headquarters for Microsoft Research at Building 99, the first of seven new sites on the software giant's West Campus.

West Campus will feature a central campus commons, offering employees a range of facilities including a post office, a mini-spa, a bookstore and 12 food venues, all planned for completion in April 2009.

Microsoft's Entertainment and Devices Division will occupy four of the seven new buildings.

"Continuing to build a world-class campus in Redmond is critical to a company like Microsoft that has innovative people as its greatest asset," said Chris Liddell, chief financial officer at Microsoft, who is overseeing the expansion.