The Biodiversity Heritage Library (BHL) is a digital library of over 50 million pages of literature from natural history and biodiversity. It is a collaboration of 12 major natural history and botanical libraries. BHL provides open access to its literature and has over 800,000 annual visitors from over 200 countries seeking information on systematics, taxonomy, and nomenclature. Users access BHL directly as well as through links from sites like Encyclopedia of Life, Wikipedia, and search engines. BHL is working to connect its literature to field notes, specimens, and other research to provide more integrated access to biodiversity information.