One of the main limitations in using ontologies in modern information systems is due to the fact that the design and maintenance of ontologies is a complex activity that requires a specific background in formal logics and data semantics. In this paper, we present the iCoord coordination system [1], [2], which aims at supporting content managers and domain experts in the process of defining and maintaining domain ontologies. In particular, we describe the Natural Language Explanation tool (NLE) of iCoord for ontology knowledge authoring.