You might also be interested in OwlEd2
for OWL DL.
is a Multi Platform OWL DL
knolwedge base manager. OWLed2
is not just YAOE (Yet Another Ontology Editor); it embeds and uses the reasoner Pellet in order to manage a knowledge base written in OWL DL. With OWLed2
it is possible both to edit an OWL DL knowledge base and to query it in order to extract new information from explicitly stated one. It has been developed by Data Over Ontological Models
You can DOWNLOAD and use it. It's free!