This book presents a broad panorama of the algorithmic methods used for processing texts. For this reason it is a book on algorithms, but whose object is focused on the handling of texts by computers. The idea of this publication results from the observation that the rare books entirely devoted to the subject are primarily monographs of research. This is surprising because the problems of the field have been known since the development of advanced operating systems, and the need for effective solutions becomes essential because the massive use of data processing in office automation is crucial in many sectors of the society. In 1985, Galil pointed out several unsolved questions in the field, called after him, Stringology (see [12]). Most of them are still open.

In a written or vocal form, text is the only reliable vehicle of abstract concepts. Therefore, it remains the privileged support of information systems, despite of significant efforts toward the use of other media (graphic interfaces, systems of virtual reality, synthesis movies, etc.). This aspect is still reinforced by the use of knowledge databases, legal, commercial, or others, which develop on the Internet. Thanks, in particular, to the Web services.

The contents of the book carry over into formal elements and technical bases required in the fields of information retrieval, of automatic indexing for search engines, and more generally of software systems, which includes the edition, the treatment, and the compression of texts.