The development of particle accelerators involves special challenges for both humans and machines. Time and again it is necessary to push back the frontiers of science and technology. A close cooperation with industry is essential in this respect. Over more than 50 years DESY has accumulated vast experience of accelerator development, construction and operation, and is one of the world’s leading authorities in this field. DESY develops, builds and operates particle accelerators for two areas of research: photon science and particle physics.