OWLSharp is an API built atop RDFSharp with the goal of providing semantic expressivity for:

• Modeling OWL2 ontologies (with tested Protégé compatibility)
• Exchanging them using standard OWL2 formats (OWL2/XML) and also RDF formats (via RDFSharp)
• Reasoning on them with a set of 25 intelligent OWL2 inference rules
• Validating them with a set of 29 wide spectrum OWL2 analysis rules

Under development (v4.1): SWRL modeler and reasoner