This paper is a presentation of ONTO-DLP, an extension of Disjunctive Logic Programming (DLP) for complex knowledge modelling. ONTO-DLP enhances DLP by constructs coming from other knowledge representation formalisms, namely, Datalog and Ordered Logic. The former provides suitable abstraction mechanisms for complex objects handling, while the latter provides support for default reasoning. Such features make ONTO-DLV a powerful language for ontology specification and reasoning.