ParkenDD is an OpenData project. This means it uses open data from public sources such as government websites. The target of OpenData is to publish as much data as possible, for example weather and traffic data.
ParkenDD uses public data from different sources. Many cities in Germany use parking guidance systems and publish their data. ParkenDD collects this information and gives the user the ability to view data from multiple sources at one spot.
More about ParkenDD and OpenData (german) »Dresden does not only have parking data but many other fields where data wants to be published. The people from offenesdresden.de have many projects like election data or an interactive travel guide.
More about OpenData in Dresden (german) »ExCELL Mobility is a pilot project that aims to provide services through a self organized platform and real time data.
More about ExCELL Mobility (german)