information open data

Good morning,
I'm a Student and I'm attending Political Science at the University of Padua (Italy). I'm attending the course "e-democracy and e-government".
I'm studying the devolopment of Open Data in the European Union. I'm trying to understand how Open Data released by government are being used and re-used by the public, private and civil society sectors. 
Are there Open data Initiatives or contests? I would like to know if (and which) new successful application or services have been developed by Open Data released by government.
I look forward to hearing from you,
Thank you
Serena Scattolin