The Joint European Torus (JET) investigates the potential of fusion power as a safe, clean, and virtually limitless energy source for future generations. The largest tokamak in the world, it is the only operational fusion experiment capable of producing fusion energy. As a joint venture, JET is collectively used by more than 40 laboratories of EURATOM Associations. The European Fusion Development Agreement (EFDA), which was created in 1999 to co-ordinate European fusion research under the EURATOM Treaty, provided the work platform to exploit JET in an efficient and focused way. EFDA underwent a restructuring in 2013 and is now succeeded by EUROfusion, the European Consortium for the Development of Fusion Energy.