R is an integrated suite of software facilities for data manipulation,
calculation and graphical display. Among other things it has

* 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 directly
  at the computer or on hardcopy, and

* a well developed, simple and effective programming language (called
  `S') which includes conditionals, loops, user defined recursive
  functions and input and output facilities. (Indeed most of the
  system supplied functions are themselves written in the S language.)