This paper presents a totally generic client - server model for accessing legacy and new databases according to the three tier architecture principles It is based on an integrated environment that eases the dynamic creation and instantiation of secure web applications that access multiple database management systems. Emphasis is placed on the ability to query almost any type of relational database and queries can simultaneously address a multitude of data sources. The information is collected, assembled and presented to users depending on a possible set of user profiles. These profiles originate from work on securing the conduct of clinical studies. This has been achieved in the context of the E U funded project HARP (Harmonisation for the Security of Web Technologies and Applications). The generic character of the model is exploited through an accompanying set of development tools. This permits efficient and effective creation and maintenance of applications in several domains of health telematics and beyond. Main merit is the lightweight character of the resulting platform, whereby all necessary instantiations are accomplished through a set of related XML documents.