Thisisnowthefourtheditionof"TheBasicsofS-Plus"since1997.S-Plus saw a steady growth in popularity, and it established itself in many edu- tional and business places as a major data analysis tool.S-Plus is valued for its modern, interactive data analysis environment, whether it is the p- mary system or a complement to other standards like SAS (the latter is in particular true for the industry we work in, pharmaceuticals). We have followed the various releases with new editions of our book, introducing over time major changes like the incorporation of S Version 4 (the underlying language),...