R Statistical Programming Language <www.r-project.org>

R is a language and environment for statistical computing and graphics.  It 
is a GNU project which is similar to the S language and environment which 
was developed at Bell Laboratories (formerly AT&T, now Lucent Technologies) 
by John Chambers and colleagues.  R can be considered as a different 
implementation of S.  There are some important differences, but much code 
written for S runs unaltered under R.