The Parisian Urbanism Agency has launched a cartographic web application CASSINI (Apur Consultation of the Spatial Server via Internet and Intranet), which enables everybody to consult a collection of data on the Parisian metropolis, with geographic reference data, historical maps, regulatory data and in the near future, social, economic, statistical and environmental data as well as that linked to development projects. The very precise detail makes it possible to explore each parcel of land historically, in the present day and its possible evolution in the future. This tool has been developed by the Parisian Urbanism Agency, Apur, in partnership with the City of Paris, the Departments of Hauts-de-Seine, Seine-Saint-Denis and Val-de-Marne, the Paris Fire Brigade, the Public Finance General Directorate, the Paris City Transport Authority, RATP and the companies ESRI and InterAtlas.