The main project goals are the development of a Web GIS application and, simultaneously, studying the applicability of computational geometric algorithms in the specific GIS. For the Greek part, the stimulus for this multidisciplinary project was the need to design a Web GIS for areas with wide geographic distribution such as the islands of the Eastern Aegean that meet serious problems with specific environmental factors; for instance often fire or sudden rainfall that result in floods every year in this region. Hence, a flexible and dynamic tool that enables continuous update of the environmental conditions in the area is of great necessity for the local authorities and for the academic community as well. On the other hand, the Slovenian team is also vigorously interested in the development of the Web GIS from another perspective. Designing geometrical algorithms and examining their functionality in specific software is remarkably intriguing. The attempt to identify missing algorithms’ functionalities, possibly met on an actual application, promotes knowledge and improves the algorithms’ effectiveness.