The development of large web applications has focused on the use of increasingly complex architectures based on the layer architectural pattern and different development frameworks. Many techniques have been proposed to deal with this increasing complexity, mostly in the field of model-based development which abstracts the architects and designers from the architectural and technological complexities. However, these techniques do not take into account the great technological variability of these architectures, and therefore limit the architectural options available for their users. In this paper we describe a metamodel that captures the technological details involved in the use of a specific framework. Using this metamodel, we are able to model the technological knowledge required to take advantage of a number of development frameworks. Using these models as part of a model-driven development process, we are able to incorporate technological variability into the modelbased development of multilayer applications. This approach keeps complexity under control whilst flexibility on choosing technologies is not penalized.Index Terms-Multilayer architectures; design patterns; model-driven development; development frameworks; metamodelMultilayer architectures; design patterns; model-driven development; development frameworks; metamodel.