In a world of linked data, in which anyone can say anything about anything, how do we build systems in which users and apps are easily allowed to express useful, helpful things? What tools can we use which allow new systems to grow easily and work well together? Ontology languages The RDF schema languages, RDF Schema and OWL, tell you implications one can draw from RDF Model data. They also tell you what things do not make logical sense. Therefore in a sense they indirectly have the function ...