In order to develop context-aware applications for ubiquitous computing environments we have defined an MDA approach that defines three layers of models. The first layer captures the conceptual characteristics of the application. This layer defines three complementary points of view of the system that are used to build the task, space and social views of the system. The second layer defines the software characteristics of the application. It is composed by three new complementary points of view of the system that are used to build the referential space, the information flow and the entity context views of the system. Finally, the third layer defines the deployment environment of the system according to the views generated by the second layer.