The book presents the state of the art in high performance computing and simulation on modern supercomputer architectures. It covers trends in high performance application software development in general and specifically for parallel vector architectures. The contributions cover among others the field of computational fluid dynamics, physics, chemistry, and meteorology. Innovative application fields like reactive flow simulations and nano technology are presented. Furthermore, the use of supercomputers in the growing field of medical simulations is shown. All papers were chosen from presentations given at the fourth Teraflop Workbench Project Workshop held at the Höchstleistungsrechenzentrum Stuttgart (HLRS) in March 2006.