Supercomputers are seen as being at the forefront of computer technology and as ideal tools for researchers in such fields as aerospace, electronics and weaponry. This study for the general, computer-literate audience examines computer architecture, the technologies used in building supercomputers and the constraints and future of their design, dealing with software, numerical methods and performance in terms of practical applications. Further technological possibilities and new hardware are also discussed. Most formulations of problems have been explained and mathematical formulae have been deliberately kept to a minumum. In cases where technical material has had to be included, text has been provided which aims to enable the reader to follow the thread of the argument without needing to understand the technical formulation of the problem under discussion. This revised edition of the text includes two chapters dealing with improvements in supercomputer technology and novel architectures.