The desire to write a book on Objective Caml sprang from the authors' pedagogical experience in teaching programming concepts through the Objective Caml language. The students in various majors and the engineers in continuing education at Pierre and Marie Curie University have, through their dynamism and their critiques, caused our presentation of the Objective Caml language to evolve greatly. Several examples in this book are directly inspired by their projects.

The implementation of the Caml language has been ongoing for fifteen years. Its  development comes from the Formel and then Crist al projects at INRIA, in collaboration with Denis Diderot University and the Ecole Normale Superieure. The continuous efforts of the researchers on these teams, as much to develop the theoretical  underpinnings as the implementation itself, have produced over the span of years a language of very high quality. They have been able to keep pace with the constant evolution of the field while integrating new programming paradigms into a formal framework. We hope through this exposition to contribute to the widespread diffusion which this work deserves.

The form and the foundation of this book wouldn't be what they are without the help of numerous colleagues. They were not put off by rereading our first manuscripts. Their remarks and their comments have allowed this exposition to improve throughout the course of its development. We wish particularly to thank Maria-Virginia Aponte, Syl- vain Baro, Christian Codognet, Helene Cottier, Guy Cousineau, Pierre Cregut, Titou Durand, Christophe Gonzales, Michelle Morcrette, Christian Queinnec, Attila Raksany and Didier Remy.

The HTML version of this book would not have seen the light of day without the tools hevea and VideoC. A big thank you to their respective authors, Luc Maranget and Christian Queinnec, who have always responded in the briefest intervals to our questions and our demands for changes.