Internet Archive was founded in 1996 as a non-profit project and is dedicated to the long-term archiving of digital data, which is freely-accessible to the public. In principle, the project saves and archives everything that can be digitised: webpage screenshots, Usernet posts, films, TV shows, audio recordings, books, and software. Across three Californian cities, data centres save the data on 20,000 hard drives. As of 2014, 18.5 petabytes of data had been collated. For security reasons, there are two other international servers (in Alexandria and Amsterdam) on which the information is mirrored.
Often used as a synonym for Internet Archive, the “Wayback Machine” is its most important project and allows users to call up old versions of saved websites. As of June 2015, it provides access to 482 billion sites. Similarly, “The Million Book Project” digitises all books whose copyright has expired and makes them available for free download.