Facebook launched its website on February 4, 2004, developed by Mark Zuckerberg with his Harvard roommates and friends. By summer 2004, the company moved out to Palo Alto and by 2007, Facebook was growing rapidly and opened to the general public, previously still closed to just colleges.
In Feb 2011, after gobbling numerous buildings and space in downtown Palo Alto, Facebook consolidated and moved to Menlo Park to the old Sun Microsystems buildings on the west side of the Dumbarton Bridge. One of the best representations of the reuse of facilities in the area, the back of the Thumbs Up Sign pictured above is the old Sun sign.