A series of important applications of combinatorics on words has emerged with the development of computerized text and string processing, for example in biology and linguistics. The aim of this volume the third in a trilogy, is to present a unified treatment of some of the major fields of applications. After an introduction that sets the scene and gathers together the basicfacts, there follow chapters in which applications are considered in detail. The areas covered include: core algorithms for text processing, natural language processing, speech processing, bioinformatics, and several areas of applied mathematics such as combinatorial enumeration and fractal analysis. No special prerequisites are needed, and no familiarity with the application areas, or with the material covered by the previous volumes, is required. The breadth of application, combined with the inclusion of problems and algorithms and a complete bibliography, will make this book ideal for graduate students and professionals in mathematics, computer science, biology and linguistics.