The SwissFEL X-ray free-electron laser is a unique light source that addresses important needs in energy supply, the environment, medicine, and materials for new technology. It is an important element in maintaining Switzerland’s leading position in scientific research. Experiments at SwissFEL will lead to an entirely new level of understanding of matter in biology, chemistry, engineering and materials science. SwissFEL makes ultrashort pulses of X-rays with the properties of laser light. It will be a billion times brighter than the synchrotron light at the Swiss Light Source SLS. The X-ray pulses will be powerful enough to make movies of atoms and molecules in motion. SwissFEL is complementary to the SLS. The two research facilities will operate together to meet the growing demand for state-of-the-art beams of X-rays and ultraviolet light. PSI scientists and engineers collaborate with other research centres worldwide to share expertise and push forward free-electron laser technology.