Tableau is a tool that allows you to create visualizations very quickly on any data set. With this tool you can create your own dashboards and thus take advantage of the power that Tableau gives you to perform data analysis. Tableau's Web Data Connectors allow you to connect the tool with external data to obtain it automatically and very easily. ISTAC has developed its own set of web connectors for Tableau to simplify the reuse of published information.
QGIS (previously also called Quantum GIS) is an open source Geographic Information System (GIS). ISTAC has developed its own extension to facilitate access to indicators and maps from QGIS.