This section describes the conceptual models, ontologies and knowledge bases, used in the MOLTO KRI as a context background in the RDFDB component.

• PROTON ontology - a lightweight upper-level ontology defining about 300 classes and 100 properties in OWL Light.
• The default KRI knowledge base - common world knowledge that contains information about people, organizations, locations, and job titles.

Most applications of the KRI require extending the conceptual models with domain ontologies and the underlying knowledge base with domain specific entities and facts.