The SEFAGI project (Simple Environment For Adaptable Graphical Interfaces) aims at designing an architecture to adapt applications to multi-terminal environments. Our main objectives are: (i) allow the end-users to describe their user interfaces and automatically generate the entire corresponding code and (ii) make the code generation adaptable to any kind of Java-enabled terminal. Our generator currently allows the generation of user interfaces for three types of target platforms: standard terminals, limited mobile terminals and high capacity mobile terminals. This led us to define a language for describing the target platforms, independently from windows descriptions. New platforms are thus easier included