Abstract: The large amount of data available in Geographic Information System is often difficult to manage for a standalone GIS installation. In this case, a client-server approach is adviced, especially dealing with multiple architectures and data formats. The creation and management of centralised repository for GIS data offer many advantages but pose some problems. In particular, the interoperability of the server with a mixed set of clients is troublesome. Free and Open Source Software (FOSS) provides an appealing solution to this problem, but real usability must be checked. Many GIS software, both proprietary and Open Source declare a complete interoperability with the most common Database and GeoDataBase formats, but not many real test can be found in literature. This paper describes the set up of a spatial data base management system and reports a series of tests of connection of various GIS clients. Main results, problems and some possible solutions are described.