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 which 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.