— The design and the implementation of software for mobile computers and for pervasive computing environments entail several issues and lead to new requirements. Applications must handle at run-time the heterogeneity of delivery contexts in terms of devices features, network bandwidth, input and output modalities, operating systems, and so forth. In this paper, we propose a practical approach for enabling platform independent application development and on-the-fly generation of user interfaces based on object introspection and device adaptation.