Abstract
In this paper we present a novel framework for a markup language for the definition of user interfaces. Such framework includes the possibility and mechanisms for user interfaces adaptability and scalability. The typical scenario in which such a markup language would be suitable is an application distributed over many peers of dif-ferent performances (in terms of processing power, display adapter, input devices) and connection types (in terms of speed and latency). After giving a brief state-of-the-art review we propose a new request/response mechanisms which allows optimal network and client’s resource utilization by adapting the user interface to the client. For the illustration of the concept presented we give an example of a virtual web application with two different clients (in terms of properties and network connection type).