DESY, Germany's leading particle physics and synchrotron radiation laboratory, and the DOE's SLAC, established a unique international collaboration for the development of X-ray free-electron lasers. Generating X-ray pulses ten billion times brighter and a thousandfold shorter in duration than existing sources, these ultra-brilliant beams will explore previously inaccessible realms in the chemical, biological and materials sciences as well as in nanoscale phenomenology, and atomic and plasma physics.