Facebook Platform, an application program interface (API) that developers can use to build applications within the social-networking site Facebook, has created a Silicon Valley gold rush. The API gives developers a great deal of access to Facebook's social resources. Developers can build applications that fit in several slots on users' profile pages; have access to information from users' profiles, friend lists, and friends' profiles; publish information through the News Feed on Facebook; and send alerts and requests. Users can add and remove applications with the click of a button. Since the launch of Facebook Platform in May, more than 2,000 applications have been made available on Facebook.