R is a free software environment for statistical computing and graphics. Its integrated suite of software facilities enables data manipulation, calculation, and graphical display. The environment compiles and runs on a wide variety of UNIX platforms, Windows, and MacOS. The S language is often the vehicle of choice for research in statistical methodology, and R provides an open-source route to participation in that activity. 

The R environment includes:

• an effective data handling and storage facility,
• a suite of operators for calculations on arrays, in particular matrices,
• a large, coherent, integrated collection of intermediate tools for data analysis,
• graphical facilities for data analysis and display either on-screen or on hardcopy, and
• a well-developed, simple, and effective programming language which includes conditionals, loops, user-defined recursive functions, and input and output facilities.

One of R’s strengths is the ease with which well-designed, publication-quality plots can be produced, including mathematical symbols and formulae where needed.