The computation of patterns in strings is a fundamental requirement in many areas of science and information processing. The operation of a text editor, the lexical analysis of a computer program, the functioning of a finite automaton, the retrieval of information from a database - these are all activities which may require that patterns be located and computed. In other areas of science, the algorithms that compute patterns have applications in such diverse fields as data compression, cryptography, speech recognition, computer vision, computational geometry and molecular biology.