In this paper we discuss the role of modelling and of EMF (Eclipse Modeling Framework) and GMF (Eclipse Graphical Modeling Framework) in the design and development of supports for eLearning applications. A model driven approach to eLearning applications is presented, rooted on the explicit representation of the model of the didactic content, based on a metamodel language expressed in Ecore. Besides exploiting the integration of Java, XML and UML provided by EMF, we introduce a Prolog-based representation of models as a more convenient way to overcome the gap between the user level and the technology level and as a mean to reduce the cost of design and implementation of learning strategies. Working in a MDA perspective, the tool exploits GMF and Jet (Java Emitter Templates) to produce code for a knowledge based, SCORM® compliant Platform Specific Model. The content model provides the Platform Independent Model that allows to achieve the intended behavioural semantics.