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In this paper we present the iconic query system of the KIM environment, providing the user with a homogeneous access to distributed, heterogeneous and multimedia databases through a modality independent of the specific underlying environments (i.e. DBMS and physical installations).A prototype of this system is being designed and implemented by a European Consortium under the KIM project, within the European ESPRIT programme. The characteristics of the query system have been identified on the basis of several research contributions, integrated and refined with the actual discussion and validation with a significant number of users in real working environments. Now, a significant nucleus of the prototype is operating and is being experimented with real databases at several pilot sites in Europe, and mainly at the European Space Agency in Frascati (Italy).The basic assumption underlying the KIM approach, is that conceptual (graphical) models can represent a suitable and integrated method to permit the user to access information from distributed, heterogeneous databases without needing to know the actual organisation, models and physical products.Different requirements and classes of users can be envisaged for a generic query system. An analysis of these categories is provided, discussing the most effective interfacing modalities for the individual cases.On the basis of the depicted considerations, the system provides both iconic and diagrammatic interfaces. The adoption of mixed interface (including both icons and ER diagrams) is quite innovative in this field, both as concerns the research activities and its actual implementation in industrial environments.

The technological evolution and the increasing number of the hardware and software products available on the market make a wide range of possible solutions available to the system designer when defining the architecture to be used for implementing new computer--supported applications.

Release 2.0 of GDOC, a tool for computer aided design of data base applications, is described.GDOC allows interactive specification of the conceptual schema of the application, expressed in an enriched Entity-Relationship Model, produces the relevant documentation by means of traditional printouts, as well as allowing a graphical definition of the conceptual schema. Moreover GDOC automatically generates the operating programs for accessing the concepts in the schema.Experiences of use of GDOC are discussed and further research directions are outlined.

Release 2.1 of GDOC, a tool for computer-aided design of database applications, is described.GDOC provides for the interactive specification of the conceptual schema of the application, expressed in an enriched Entity-Relationship Model and produces the relevant documentation by means of traditional printouts, as well as allowing a graphical definition of the conceptual schema. Moreover, GDOC automatically generates the physical database and the operating programs for accessing the concepts in the schema in a dBASE II environment.Experiences of use of GDOC are discussed and further research directions are outlined.