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 vector-based systems and heterogeneous architectures. The application contributions cover computational fluid dynamics, fluid-structure interaction, physics, chemistry, astrophysics, and climate research. Innovative fields like coupled multi-physics or multi-scale simulations are presented. All papers were chosen from presentations given at the fifth Teraflop Workshop held in November 2006 at Tohoku University, Japan, and the sixth Teraflop Workshop held in March 2007 at the Stuttgart High Performance Computing Center (HLRS), Germany.