Progressive HTTP-based querying of remote databases within the Marmotta iconic VQS

The Marmotta system described serves as a graphical interface for querying remote databases which have already been provided with a software layer to communicate with the WWW world. It can be used as a convenient alternative to the forms embedded within the WWW clients. Within Marmotta, icons are used to present the domain of interest and the retrieval requests in an original way, and are managed by the user in a direct manipulation style. The ease-of-use characterizing form-based interfaces is preserved (users need not know the structure of the database) while expressive power is greatly increased. Moreover, Marmotta provides comfortable mechanisms for browsing, manipulating and reusing query results as well as previous queries, thus strongly supporting non-motonic, progressive query processes.