A geographic information system (GIS) is a system designed to capture, store, manipulate, analyze, manage, and present spatial or geographic data. GIS are becoming increasingly relevant for public administrations as policies become more and more location-data sensitive (from the traditional national mapping services, to the management of cadastrial information, the environmental policies, the management of territory, telecommmunications and transports, and so on). Several local and national public administrations have developed free and open source GIS that are made available through this collection, together with information and experiences to be exchanged among stakeholders and practitioners.