In the heterogeneous scenario of standards supporting the deployment of Interactive Television, interoperability seems to be the key issue to grant a deeper market penetration of the digital television in everyday life as well as adequate return of investments to the actors involved in the value chain. This paper presents an innovative architecture to support application interoperability across different frameworks (i.e. DVB-T, ISDB-T, ACAP, ISDTV, etc.) based on GEM standard, promoting the implementations of iTV XML-based application available worldwide. The theoretical approach introduced in the document will be evaluated in a real learning scenario, both in Europe and in Brazil; the paper presents preliminary results in terms of functionalities and user interface to be evaluated and tuned, according to the user centered design approach.