Private participation in the provision of public infrastructure and services has a long history dating back to the days of the Roman Empire. However, during the last few decades PPPs began to proliferate as a specific form of such provision. However, the verdict on PPPs is still a mixed picture. This special EBook brings together several papers addressing a variety of issues within PPPs. It covers reviews as well as reports varying levels of success of PPP projects around the world. It represents a critical milestone in the quest to review the demonstrable potentials and prospects of PPPs, and identification of areas for improvement.