Implementing geoportals: applications of distributed GIS

As GIS implementations mature and GIS use expands beyond the current core GIS community the need to discover and disseminate GIS capabilities grows. The Internet and the age of distributed computing provide the technical framework on which distributed GIS is built. As key application of distributed GIS, geoportals provide a gateway to discover and access geographic Web services. Four key geoportal projects are presented that help to define distributed GIS, and illustrate the challenges to be met in order to achieve the goal of wider GIS usage.