The Encyclopedia of Life (EOL) is a free, online collaborative encyclopedia intended to document all of the 1.9 million living species known to science. It is compiled from existing databases and from contributions by experts and non-experts throughout the world. It aims to build one "infinitely expandable" page for each species, including video, sound, images, graphics, as well as text. In addition, the Encyclopedia incorporates content from the Biodiversity Heritage Library, which digitizes millions of pages of printed literature from the world's major natural history libraries. The project was initially backed by a US$50 million funding commitment, led by the MacArthur Foundation and the Sloan Foundation, who provided US$20 million and US$5 million, respectively. The additional US$25 million came from five cornerstone institutions—the Field Museum, Harvard University, the Marine Biological Laboratory, the Missouri Botanical Garden, and the Smithsonian Institution. The project was initially led by Jim Edwards and the development team by David Patterson. Today, participating institutions and individual donors continue to support EOL through financial contributions.