Internet Archive founders Brewster Kahle and Bruce Gilliat launched the Wayback Machine in 2001 to address the problem of website content vanishing whenever it gets changed or shut down. The service enables users to see archived versions of web pages across time, which the archive calls a "three dimensional index". Kahle and Gilliat created the machine hoping to archive the entire Internet and provide "universal access to all knowledge."
The name Wayback Machine was chosen as a reference to the "WABAC machine" (pronounced way-back), a time-traveling device used by the characters Mr. Peabody and Sherman in The Rocky and Bullwinkle Show, an animated cartoon. In one of the animated cartoon's component segments, Peabody's Improbable History, the characters routinely used the machine to witness, participate in, and, more often than not, alter famous events in history.
The Wayback Machine began archiving cached web pages in 1996, with the goal of making the service public five years later. From 1996 to 2001 the information was kept on digital tape, with Kahle occasionally allowing researchers and scientists to tap into the clunky database. When the archive reached its fifth anniversary in 2001, it was unveiled and opened to the public in a ceremony at the University of California, Berkeley. By the time the Wayback Machine launched, it already contained over 10 billion archived pages.
Today the data is stored on the Internet Archive's large cluster of Linux nodes. It revisits and archives new versions of websites on occasion (see technical details below). Sites can also be captured manually by entering a website's URL into the search box, provided the website allows the Wayback Machine to "crawl" it and save the data.