City Focus is a web-based interactive 2D and 3D GIS application to find thebest place in a city to live as well as to pass shorter staying. The user canselect among different criteria and decide their importance by assigningweights to each of them. The application provides thematic maps displayinginsights on the places which better fit the user’s preferences. The resultingmap is computed through map algebra by means of Web Coverage ProcessingService WCPS provided by RASDAMAN Database Management System. Datavisualization is mainly based on NASA Web WorldWind open-source virtual globe.The app exploits exclusively open data as well as Free and Open SourceSoftware (FOSS) for its implementation by enabling continuous improvementswhile minimizing development costs. City Focus is a work-in-progress application, winner of the MYGEOSS third callfor innovative Apps, launched by the European Commission. The callfocused on developing applications of European relevance able to provide userswith quantitative or qualitative information on the changing environment,taking into account broad environmental or social themes across geographicscales, stressing the use of openly available or crowd-generated data indifferent domains addressing citizens’ needs (Raglia & Craglia, 2015). CityFocus is a web-based interactive 2D and 3D GIS application to find the bestplace in a city to live, or to pass shorter staying. The user can select amongdifferent criteria and decide their importance by assigning weights to each ofthem. The application provides thematic maps displaying insights on the placeswhich better fit the user’s preferences. The resulting map is computed throughmap algebra upon a cascade of pre-built raster maps. Users are guided in therequests through a predefined list of criteria including: air quality,precipitation, terrain morphology (e.g. slope, solar exposure, etc.),temperature, proximity to urban facilities (e.g. schools, transportations,sports fields, cultural attractions, healthcare centers, parking lots, shops,etc.), presence of public spaces, land use characteristics (e.g. commercialareas, residential areas, etc.), population density, traffic or internetconnection.