The linguistic conformance and the ontological conformance between models and metamodels are two different aspects that are frequently mixed. Particularly, this situation occurs in the EMF framework and it has resulted in some well known problems. The most relevant to us is the incapability to load metamodels at runtime, or even to modify the metamodels already in use. In this paper we present a strategy to solve this problem by separating the ontological and the linguistic aspects of a metamodel and a metamodeling framework. The strategy has been implemented in a graphical editor and is motivated in the context of Enterprise Architecture Projects.