The W3C OWL Working Group published seven documents related to the OWL 2 Web Ontology Language. OWL 2 extends OWL adding new features that users have requested and that software providers are prepared to implement. The documents are:
- Structural Specification and Functional-Style Syntax
- Direct Semantics
- RDF-Based Semantics (First Public Draft)
- Mapping to RDF Graphs
- XML Serialization
- Conformance and Test Cases (First Public Draft)
The first three documents form the technical core of OWL 2, which has both a traditional “direct” semantics (for OWL DL) and a new “RDF-based” semantics (for OWL Full). Documents 4 and 5 specify two different serializations for OWL ontologies, one based on RDF and one using XML more directly. Document 6 defines useful subsets of OWL which may be easier to implement or may better meet certain performance requirements. Finally, document 7 specifies conformance and will later enumerate the OWL 2 test cases. Five other documents are under development; but they are not yet ready for public review.