The novel and crucial point of this paper is the illustration of the application of close ontology based meta-modeling to defining the open ontology based construction of modeling languages (meta-models). This approach is a generalization of Object Management Group (OMG) standards related to Model Driven Architecture (MDA). The existing modeling tools supporting the traditional approach can be reused when open ontology based meta-modeling tools are implemented. This paper describes Context-Driven Meta-Modeling Meta-Modeler (CDMM-Meta-Modeler) ‒ the Eclipse Plugin that constitutes such an open ontology based meta-modeling tool. The tool constitutes an implementation of the diagramming aspect for the Context-Driven Meta-Modeling Framework (CDMM-F), which is one of several possible implementations of the Context-Driven Meta-Modeling Paradigm (CDMM-P).