Abstract. We introduce Naturalowl, an open-source multilingual natural language generator that produces descriptions of instances and classes, starting from a linguistically annotated ontology. The generator is heavily based on ideas from ilex and m-piro, but it is in many ways simpler and it provides full support for owl dl ontologies with rdf linguistic annotations. Naturalowl is written in Java, and it is supported by m-piro’s authoring tool, as well as an alternative plug-in for the Protégé ontology editor.