Project Gutenberg
The first and largest single collection of free electronic books, or e-books. Michael Hart, founder of Project Gutenberg, invented e-books in 1971 and continues to inspire the creation of e-books and related technologies today. There are over 20,000 free e-books in the online catalog.

By: Project Gutenberg Literary Archive Foundation

LibriVox
A digital library of free public domain audiobooks, read by volunteers. The recordings are mostly in English, however recordings are available in over 20 languages. The goal is to make all public domain books available, for free, in audio format on the Internet.

By: LibriVox