Ontology editors have an important role on building, saving, and handling concept maps. Protégé is an open source ontology editor developed by Stanford University and widely used. Protégé software is able to define classes and relationships between classes. The latest version of Protégé supports XML, RDF, and OWL formats. Although Protégé is available to the public, some researchers prefer developing their own ontology editors like OntoEdit (Maedche & Staab, 2001). OntoEdit program offered more tools to edit ontologies than Protégé version at that time and then it was later commercialized. Ontology editors allow the assignment of relation types to connect concepts.