ITER stands for International Thermonuclear Experimental Reactor. It is a collaboration between Europe, Canada, Japan and Russia, and is planned to be the first fusion reactor to produce more power than is required to run it. About 2-3 times the size of the largest current reactors (JET and JT-60), and using new techniques such as superconducting coils, it will hopefully pave the way for a demonstration fusion power plant.