The book presents the state of the art in high performance computing and simulation on modern supercomputer architectures. It covers trends in hardware and software development in general and specifically the future of high performance systems and heterogeneous architectures. The application contributions cover computational fluid dynamics, material science, medical applications and climate research. Innovative fields like coupled multi-physics or multi-scale simulations are presented. All papers were chosen from presentations given at the 14th Teraflop Workshop held in December 2011 at HLRS, University of Stuttgart, Germany and the Workshop on Sustained Simulation Performance at Tohoku University in March 2012.