Many Web applications offer the possibility of distributing their data and their business logic between the client and the server, also allowing an asynchronous communication between them. These features, originally associated with the arrival of Rich Internet Applications (RIA), remain particularly relevant and desirable. In the area of RIA, there are few proposals that simultaneously consider these features, adopt Model Driven Development (MDD), and use implementation technologies based on scripting. In this work, we start from MoWebA, an MDD approach to web application development, and we extend it by defining a specific architecture model with RIA functionalities, supporting the previously mentioned features.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCIA