This book is intended for both statisticians and non-statisticians alike. It is hoped, in particular, that it will appeal to practitioners of extreme value modeling with limited statistical expertise. The mathematical level is elementary, and detailed mathematical proof is usually sacrificed in favor of heuristic argument. Rather more attention is paid to statistical detail, and many examples are provided by way of illustration. All the computations were carried out using the S-PLUS statistical software program, and corre-sponding datasets and functions are available via the internet as explained in the Appendix.