Facebook is a social networking service launched on February 4, 2004. It was founded by Mark Zuckerberg with his college roommates and fellow Harvard University student Eduardo Saverin. The website's membership was initially limited by the founders to Harvard students, but was expanded to other colleges in the Boston area, the Ivy League, and gradually most universities in Canada and the United States, corporations, and by September 2006, to everyone of age 13 and older with a valid email address.