BioPortal ("http://bioportal.bioontology.org":http://bioportal.bioontology.org) is an open repository of biomedical ontologies that provides programmatic and web-based access to ontologies developed in OBO, OWL, Protégé frames, and RDF. Features include browsing, searching, and visualization of ontologies. Searching of integrated data resources is also possible through ontology-based indexing of biomedical resources with BioPortal ontologies.
No takes yet. Share an insight, caveat, or question.
Whetzel et al. (2009) studied this question.