It is based upon S which was developed by John Chambers of Bell Laboratories and described in the paper "Evolution of the S Language" [1]. R is considered by its developers to be an implementation of S, with semantics derived from Scheme.

R is freely available under the GNU GPL and is available for Windows, Macintosh, and many Unix operating systems.

- The R Project for Statistical Computing
- The CRAN (Comprehensive R Archive Network) Project
- Web-based interface to R