The Catalogue of Life employs a simple data structure to provide information on synonymy, grouping within a taxonomic hierarchy, common names, distribution and ecological environment. The Catalogue provides a dynamic edition, which is updated monthly and an Annual Checklist, which provides a dated, verifiable reference for the usage of names and associated data. Development of the Catalogue of Life was funded through the Species 2000 europa, 4d4Life, i4Life projects in 2003-2013, and currently by the Naturalis Biodiversity Center, Leiden, the Netherlands and Species Files group at Illinois Natural History Survey, Champaign-Urbana IL, USA.
Usage
Much of the use of the Catalogue is to provide a backbone taxonomy for other global data portals and biological collections. Through the i4Life project it has formal partnerships with Global Biodiversity Information Facility, European Nucleotide Archive, Encyclopedia of Life, European Consortium for the Barcode of Life, IUCN Red List, and Life Watch. The public interface includes both search and browse functions as well as offering multi lingual services. The Catalogue listed 300,000 species by 2003, 500,000 species by 2005, and over 800,000 species by 2006. As of 2019, the Catalogue lists 1.9M extant and extinct species. There are an estimated 14M mainly unpublished species, however this number is not certain as there is a lack of data on the possible number of undescribed insect, nematode, bacteria, fungus and many other species.
Catalogue of Life Plus
In 2015, an expert panel presented a consensus hierarchical classification of life, including some sectors not yet represented in the published Catalogue. In the same year, the Catalogue of Life, Barcode of LifeData System, Biodiversity Heritage Library, Encyclopedia of Life, and the Global Biodiversity Information Facility met to consider building a single shared authoritative nomenclature and taxonomic foundation "Catalogue of Life Plus" that could be used to order and connect biodiversity data, including content not yet in CoL but available via other sources, to serve both the users of the present Catalogue and users of extended taxonomic content using a common infrastructure. COL+ will develop a clearinghouse covering scientific names across all life, provide a single taxonomic view, and provide an avenue for feedback from content authorities.