This book is concerned with the emerging field of High Performance Reconfigurable Computing (HPRC), which aims to harness the high performance and relative low power of reconfigurable hardware–in the form Field Programmable Gate Arrays (FPGAs)–in High Performance Computing (HPC) applications. It presents the latest developments in this field from applications, architecture, and tools and methodologies points of view. We hope that this work will form a reference for existing researchers in the field, and entice new researchers and developers to join the HPRC community. The book includes: Thirteen application chapters which present the most important application areas tackled by high performance reconfigurable computers, namely: financial computing, bioinformatics and computational biology, data search and processing, stencil computation e.g. computational fluid dynamics and seismic modeling, cryptanalysis, astronomical N-body simulation, and circuit simulation. Seven architecture chapters which present both commercial and academic parallel FPGA architectures, low latency and high performance FPGA-based networks and memory architectures for parallel machines, and a high speed optical dynamic reconfiguration mechanism for HPRC. Five tools and methodologies chapters which address the important issue of productivity and high performance in HPRC. These include a study of precision and arithmetic issues in HPRC, comparative studies of C-based high level synthesis tools and RTL-based approaches, taxonomy of HPRC tools and a framework of their analysis, and an integrated hardware-software-application approach to HPRC.