<Tr> <Th> Written in </Th> <Td> C++, PHP (as HHVM) and D language </Td> </Tr> <P> Facebook is an American online social media and social networking service company based in Menlo Park, California . The Facebook website was launched on February 4, 2004, by Mark Zuckerberg, along with fellow Harvard College students and roommates, Eduardo Saverin, Andrew McCollum, Dustin Moskovitz, and Chris Hughes . </P> <P> The founders had initially limited the website's membership to Harvard students; however, later they expanded it to higher education institutions in the Boston area, the Ivy League schools, and Stanford University . Facebook gradually added support for students at various other universities, and eventually to high school students as well . Since 2006, anyone who claims to be at least 13 years old has been allowed to become a registered user of Facebook, though variations exist in the minimum age requirement, depending on applicable local laws . The Facebook name comes from the face book directories often given to United States university students . The company held its initial public offering (IPO) in February 2012, and began selling stock to the public three months later, reaching an original peak market capitalization of $104 billion, a new record . Facebook makes most of its revenue from advertisements which appear onscreen . </P> <P> Facebook may be accessed by a large range of devices with Internet connectivity, such as desktop, laptop and tablet computers, and smartphones . After registering to use the site, users can create a customized profile indicating their name, occupation, schools attended and so on . Users can add other users as "friends", exchange messages, post status updates, share photos, videos and links, use various software applications ("apps"), and receive notifications of activity . Additionally, users may join common - interest user groups organized by workplace, school, hobbies or other topics, and categorize their friends into lists such as "People From Work" or "Close Friends". Additionally, users can complain about or block unpleasant people . </P>

When did facebook start allowing everyone to join