In this chapter, we provide a basic introduction to the R system (R Development Core Team (2005)): where to get R, how to install R and how to upgrade R packages. We also show how easy it is to use R to simulate and analyze data from a simple clinical trial. The chapter ends with concluding remarks and some recommendations for further reading and references. Readers who already know and have familiarity with R can skip this chapter and go directly to any of the remaining chapters.