Nowadays, the emergence of several model-driven development (MDD) proposals that are related to multiple domains requires the definition of proper interoperability mechanisms that facilitate the reuse of knowledge in the MDD community by taking advantage of already defined modeling languages, tools, and standards. However, there are no recent studies that cover the existent interoperability alternatives in the model-driven domain nor is there a common interoperability framework. This paper confronts this situation through a systematic analysis of recent interoperability approaches that provide relevant features for MDD processes. From this analysis, a general interoperability framework is depicted, which is complemented with our contributions to solve specific interoperability issues. Therefore, we present those aspects that are already covered by existent proposals as well as those pending subjects that, from our point of view, are future challenges in order to achieve a suitable interoperability framework for MDD approaches.