Biodiversity Heritage Library"The Biodiversity Heritage Library improves research methodology by collaboratively making biodiversity literature openly available to the world as part of a global biodiversity community. ... The BHL portal provides free access to hundreds of thousands of volumes, comprising over 57 million pages, from the 15th-21st centuries."
"In addition to public domain content, BHL works with rights holders to obtain permission to make in-copyright materials openly available under Creative Commons licenses. ... Through Flickr, BHL provides access to over 150,000 illustrations, enabling greater discovery and expanding its audience to the worlds of art and design. BHL also supports a variety of citizen science projects that encourage volunteers to help enhance collection data."