Open data policies encourage the wide availability and re-use of information, with little or no legal, technical or economic constraints. The re-use of open public data contributes significantly to the development of value added services, which are products of new ways of combining and using these data. The expected beneficial effect lies in enhancing both transparency and participation, as well as creating new opportunities for actors civil society and (start-up) businesses to provide added-value services, utilizing the open data of public bodies.