ITER (International Thermonuclear Experimental Reactor) is an international nuclear fusion research and engineering project, which is currently building the world’s largest experimental tokamak nuclear fusion reactor at the Cadarache facility in the south of France. The European Fusion Development Agreement (EFDA) has published a roadmap which outlines how to supply fusion electricity to the grid by 2050 with ITER as one of its units. The roadmap to the realization of fusion energy breaks the quest for fusion energy down into eight missions. For each mission, it reviews the current status of research, identifies open issues, proposes a research and development program and estimates the required resources. It points out the needs to intensify industrial involvement and to seek all opportunities for collaboration outside Europe.