R is a free and open source software programming language and software environment for statistical computing and graphics. Distributed under the GNU General Public License version 2, R is an easy language to learn and commonly used for developing data analysis and statistical software. R compiles and runs on a wide variety of UNIX platforms, Windows and MacOS.
R is designed to allow users to add additional functionality by defining new functions. Much of the system is itself written in the R dialect of the S programming language. For computationally-intensive tasks, C, C++ and Fortran code can be linked and called at run time. Advanced users can write C code to manipulate R objects directly.
R was initially written by Robert Gentleman and Ross Ihaka, also known as “R & R” of the Statistics Department of the University of Auckland. Today, R is the result of a collaborative effort with contributions from all over the world.
The R Environment
The R environment is an integrated suite of software services for data manipulation, calculation and graphical display. R offers effective data handling and storage facility, a suite of operators for calculations on arrays, a collection of intermediate tools for data analysis, graphical facilities for data analysis and display as well as simple and effective programming language (called ‘S’) which includes conditionals, loops, user defined recursive functions and input and output facilities.
Most programs written in the R programming language are essentially ephemeral, written for a single piece of data analysis. (Source: W. N. Venables, D. M. Smith and the R Core Team; An Introduction to R)