R is a language which bears a passing resemblance to the S language developed at AT&T Bell Laboratories. It provides support for a variety of statistical and graphical analyses. R is a true computer language which contains a number of control-flow constructions for iteration and alternation. It allows users to add additional functionality by defining new functions. On platforms which support the dlopen (3) interface, Fortran and C code can be linked and called at run time. R is very close to S in both syntax and semantics, but is not identical. Whether this is a bug or feature is an open question.