Information Systems have witnessed this last decade a profound mutation because of the new constraints and requirements that have been added to the earlier systems. Users' needs have changed radically, and systems/data interoperability is more than anytime a requirement that should be fulfilled. Users require a smooth and transparent access to distributed and heterogeneous data at anytime and anywhere. The web in this sens, has allowed to alleviate these problems but is considered not mature enough to address these issues, because of other constraints that have been added such as security, the use of data and services standards, and the performances of web applications that are unfortunately less in comparison with those of thick clients. Another aspect that have changed the reality of the Information Systems world is certainly the mobility that arises a new class of constraints such as security, display and performance management, and so on.