The free movement of citizens within the European Union has been increasingly simplified, which means that, nowadays, more and more sentences are imposed on non-residents and, as a consequence, have to be enforced on the territory of other Member States. An effective application of the Framework Decision 2008/947/JHA of 27 November 2008, which allows the recognition and supervision of probation measures in a Member State other than the one that pronounced the sentence, is therefore essential in order to ensure an adequate enforcement of such sentences in the EU. However, given the disparities between probation measures existing at national levels and the lack of harmonization, the success and effectiveness of this legal instrument will highly depend on a clear understanding of those discrepancies and a profound knowledge of Member States' national probation systems. Through analysis of the national probation systems in the light of the obligations arising from the EU's Framework Decision, an EU co-funded project presents a comprehensive comparative study and promotes needed mutual understanding. It also provides legal and practical measures and tools in order to promote an appropriate and effective implementation of the legal instrument. Thanks to the support of many partners and the European Commission, this project offers a European perspective of the topic. The scientific contribution of Professors Sonja Snacken and Fergus McNeill constitutes an essential added value to the analytic study of the national probation systems. This book provides the complete research results of the project and will be a useful tool for probation services, practitioners, academics, researchers, students, and policy-makers in the area of European criminal law.