S-PLUS is a powerful tool for interactive data analysis, creating graphs, and implementing customized routines. Originating as the S language of AT&T Bell Laboratories, its modern language and flexibility make it appealing to data analysts from many scientific fields. This book explains the basics of S-PLUS in a clear style at a level suitable for people with little computing or statistical knowledge. Unlike the S-PLUS manuals, it is not comprehensive, but instead introduces the most important ideas of S-PLUS through the use of many examples. Each chapter also includes a collection of exercises that are accompanied by fully worked-out solutions and detailed comments. The volume is rounded off with practical hints on how efficient work can be performed in S-PLUS. The book is well-suited for self-study and as a textbook. The second edition has been updated to incorporate the completely revised S Language and its implementation in S-PLUS. New chapters have been added to explain how to work with the graphical user interface of the Windows version, how to explore relationships in data using the powerful Trellis graphics system, and how to understand and use object-oriented programming. In addition, the programming chapter has been extended to cover some of the more technical but important aspects of S-PLUS.