RIO
Regularity Inspector for Ontologies
RIO is an open source project. It is a framework that uses cluster analysis for the detection of syntactic regularities in ontologies.
The implementation of RIO is based on OWLAPI (http://owlapi.sourceforge.net). A standalone Java tool is used for computing regularities, which are then saved in an XML file. The RIO plugin for Protege 4 (http://protege.stanford.edu) can be used for loading and visualising the regularities in Protege ontology editor.