Supercomputing is a concept that has evolved rapidly. Computers developed under that description have existed only since the early 1970s. For most of the time since, supercomputers have been widely imagined to be expensive, arcane devices, employed in only the most esoteric functions of theoretical science and government research.

Since the mid-'90s, however, supercomputers have become more efficient, less expensive, and available for applications in all walks of life. Supercomputers are currently relied upon for computer-generated animation, for advanced design of automobiles and other complicated machinery, and in the more complex areas of medicine such as microbiology. These are in addition to the established roles of supercomputing in creating weather models, making population-growth projections and in digitally simulating nuclear detonations.

So what is a supercomputer? No universally accepted definition exists, other than that of a vague class of exceptionally fast computers. Parallel processing, that is, the practice...