ABSTRACT
An increasing number of applications need to work on data that are scattered over several independent geographical information systems. This has led to extensive research efforts in the field of interoperable information systems. The term interoperability is used in a number of different contexts. In this paper a concise explanation of the meaning of interoperability in the context of geographic information systems (GIS) is given. Current efforts in this realm are presented. Problems and challenges of the next interoperable GIS generation are identified. A proposal to meet these challenges is presented.
