Geographic Information Systems (GIS) are tools to process geographically referenced data - often in order to support decisions in spatial problems. Many GIS applications can be described as spatial decision support systems. However, spatial decision support in a narrower sense requires specialized analytical functions like optimization and multiple criteria evaluation algorithms. While most GIS functions can implicitly assist decision-making, only the specific decision support features result in explicit solutions for a decision problem. With the appearance of GIS on the Internet (called WebGIS, GIS online, or Internet map servers) there is a need to define the role of spatial decision support systems (further WebSDSS) in the context of a global information network (Rinner and Jankowski). Here are the GIS visualization services that we currently host on the portal.