This book highlights the most recent social, cultural and institutional developments of the third sector in Europe and the US. It is an inter-disciplinary text, which convenes the contribution of scholars belonging to different areas in the social science sphere (sociologists, political scientists, jurists). The focus is to evaluate the role of different agents, relationships and social policies not just from a service provision perspective but also in their true impact in shaping the society as a whole, while trying to address its most crucial needs. Furthermore, the presentation of the main and most recent empirical evidences from different contexts stimulates some very useful remarks about the current and perspective situation at a global level.