The purpose of this lexicon is to provide a concise overview and summary of R.  In some places the MS Windows operating system is assumed.

R or GNU S is a highly sophisticated and high quality computer environment for doing statistical data analysis and research.  R is very similar to S and Splus which are used worldwide by the majority of active researchers in statistics.  Official Short Description of R.

R is a scripting language.  It is very easy to write simple programs or functions in R.  R programs can be debugged quickly. R is free under the terms of a standard GNU license.  

In addition to its excellence as a scripting language for simple programs, R's other outstanding features are:

the excellence of its computer graphics for data analysis; 
high quality base functions for analysis of variance, linear models, generalized linear models; 
numerous state-of-the-art statistical libraries contributed by leading researchers in statistics.

Extensive documentation, source code and binary executables can be downloaded from the R homepage: http://cran.us.r-project.org/.

The bibliography below provides additional material.