Project Gutenberg is a volunteer effort to digitize and archive cultural works, to "encourage the creation and distribution of eBooks". Founded in 1971 by Michael S. Hart, it is the oldest digital library. Most of the items in its collection are the full texts of public domainbooks. The project tries to make these as free as possible, in long-lasting, open formats that can be used on almost any computer. As of November 2011, Project Gutenberg claimed over 38,000 items in its collection.
Wherever possible, the releases are available in plain text, but other formats are included, such as HTML, PDF, EPUB, MOBI, and Plucker. Most releases are in the English language, but many non-English works are also available.