In this paper, we present a solution for dynamic generation of Web user interfaces that can dynamically migrate among different platforms. The solution is based on a migration/proxy server able to automatically convert a desktop service into a service accessible from a different platform, such as a mobile one. This solution can support new environments where users can freely move about and change interaction device while still continuing task performance and accessing the application in a usable manner. Categories and Subject Descriptors H.5 INFORMATION INTERFACES AND PRESENTATION I2.2 Automatic Programming: Program Transformation. General Terms Design, Human Factors, Languages. Keywords Migratory Interfaces, Ubiquitous environments, Model-based design, Automatic transformations.