This book introduces High Performance Supercomputers (HPC) history and systematic classification, the most advanced HPC systems with the petaflops peak performance, the general rules to build a HPC system, and detailed overall design. It explains in depth the development of parallel computing application software, including the most advanced principles for heterogeneous parallel computing and development, summarizes the HPC applications and outlines the characteristics of the application and methodology. Finally, the HPC development and realization are predicted.