W3C’s Ontology Language (OWL)
- A layer on top of RDFS with additional possibilities
- Outcome of various projects:
- a DARPA project: DAML
- a EU project: OIL
- an attempt to merge the two: DAML+OIL
- the latter was submitted to W3C
- lots of coordination with the core RDF work
- recommendation since early 2004
