The National Center for Biomedical Ontology (NCBO) supports biomedical researchers by providing online tools and a web portal enabling them to access, review, and integrate ontological resources. The NCBO BioPortal is an open repository of biomedical ontologies, allowing users to search, browse, and visualize ontologies.
The National Center for Biomedical Ontology BioPortal API provides a RESTful interface for accessing the BioPortal. Supported services include downloads, lists by specified criteria, search, access to terms and concepts, subtree extraction, and much more. API responses may be XML or JSON formatted.