The Biodiversity Heritage Library (BHL) is a digital library that aims to make the literature of biodiversity openly available to the world. It has scanned over 70,000 volumes and 26 million pages of literature. The BHL was created in response to the "taxonomic impediment", which describes gaps in taxonomic knowledge. It works with natural history institutions around the world to digitize their collections. The BHL provides open access to this literature and develops tools to enhance access, such as name finding and citation services.