The Wayback Machine is a digital archive of the World Wide Web founded by the Internet Archive, an American nonprofit organization based in San Francisco, California. Launched for public access in 2001, the service allows users to go "back in time" to see how websites looked in the past. Founders Brewster Kahle and Bruce Gilliat developed the Wayback Machine to provide "universal access to all knowledge" by preserving archived copies of defunct web pages.