SULO offers a minimal set of classes and relations to guide the representation of knowledge in RDF/OWL.
The Ontology IRI is : https://w3id.org/sulo/
Here's the SULO Postcard showing all the classes and relations (solid line indicates connection between domain/range; dotted line indicates restriction on use in class axiom)
The ontology is available in a number of formats:
You can retrieve any of these through content type negotiation
curl -L -H "Accept: text/turtle https://w3id.org/sulo
curl -L -H "Accept: application/ld+json" https://w3id.org/sulo
curl -L -H "Accept: application/rdf+xml" https://w3id.org/sulo
curl -L -H "Accept: application/n-triples" https://w3id.org/sulo
In addition, individual versions of SULO are available through the ontology IRI pattern https://w3id.org/sulo/sulo-X.X.X.ttl All versions of the ontology are available from github
We automatically generate documentation for SULO using OntoSpy and Pylode:
FAIRness assessment performed with FOOPS!
Michel Dumontier, Remzi Çelebi, Komal Gilani, Isabelle de Zegher, Katerina Serafimova, Catalina Martínez Costa and Stefan Schulz. SULO - a simplified upper-level ontology. Proceedings of the Joint Ontology Workshops (JOWO) - Episode XI: The Sicilian Summer under the Etna, co-located with the 15th International Conference on Formal Ontology in Information Systems (FOIS 2025), September 8-9, 2025, Catania, Italy. [Paper] [Presentation]