The ISIS pulsed neutron and muon source at the Rutherford Appleton Laboratory is a world-leading centre for research in the physical and life sciences. It is owned and operated by the Science and Technology Facilities Council. It produces beams of neutrons and muons that allow scientists to study materials at the atomic level using a suite of instruments, often described as ‘super-microscopes’. It supports a national and international community of more than 3000 scientists who use neutrons and muons for research in physics, chemistry, materials science, geology, engineering and biology. The main technique used is neutron scattering. It is the most productive research centre of its type in the world. ISIS has become one of the UK’s major scientific achievements. It has changed the way the world does neutron scattering research. In particular, ISIS is an accelerator-based neutron source. Neutrons are produced when an energetic proton beam from the ISIS synchrotron accelerator hits a heavy metal target – a process called ‘spallation’. New neutron sources in other countries are based on the ISIS accelerator method of neutron production. ISIS services include Light sources, Neutron source, High performance computing and Space and Astronomy. Its recent research has impacted on health, environment, energy, technology and culture. It publishes over 400 research papers every year - and has published more than 9,000 papers during its lifetime - making it one of the most productive facilities of its type in the world.