ITER is not an end in itself: it is the bridge toward a first plant that will demonstrate the large-scale production of electrical power and tritium fuel self-sufficiency. This is the next step after ITER: the Demonstration Power Plant, or DEMO for short. A conceptual design for such a machine could be complete by 2017. If all goes well, DEMO will lead fusion into its industrial era, beginning operations in the early 2030s, and putting fusion power into the grid as early as 2040.

While ITER is being constructed and DEMO is in its conceptual phase, several fusion installations, with different characteristics and objectives, will be operating around the world to conduct complementary research and development in support of ITER. In Japan, the International Fusion Materials Irradiation Facility (IFMIF) program has begun. This installation, part of the "Broader Approach" Agreement, will test and qualify the advanced materials needed for a full-scale fusion plant.

By the last quarter of this century, if ITER and DEMO are successful, our world will enter the Age of Fusion—an age when mankind covers a significant part of its energy needs with an inexhaustible, environmentally benign, and universally available resource.