With contributions by a multinational group of academic scholars, judges and registrars of international tribunals, and experts from Non-Governmental Organizations, this book explores the role of civil society with regards to international courts and tribunals, as well as compliance mechanisms set up especially in the environmental field. The areas of human rights, international criminal law and international environmental law are the main focus of the study, in the light of the well established role of NGOs in Human Rights Courts and UN bodies as well as their remarkable success in setting up the International Criminal Court and the promising avenues which are now open in the compliance bodies of environmental law conventions. Broader questions and bodies such as the International Court of Justice, the International Tribunal for the Law of the Sea as well as European courts and tribunals are also examined.