Via a comparison of the currently used language-based components for knowledge sharing, this article first highlights the difficulties caused by the inexistence – and hence absence of exploitation – of a shared core ontology of knowledge representation languages (KRLs), i.e., (i) an ontology of KRL abstract models which represents, aligns and extends standards, and (ii) an ontology of KRL notations. For programmers, these are the difficulties of importing, exporting or translating between KRLs; for end-users, the difficulties of adapting, extending or mixing notations. This article then shows how we have built this shared core ontology plus a tool for exploiting it. We use them for specifying, parsing and translating KRLs, thus allowing their use without additional programming. This ontology can be represented in any KRL that has at least OWL-2 expressiveness. Thus, the results can easily be replicated. A Web address for the tool and the full specifications is given.