compiled library of linear algebra, probability and optimization, and with
implementations of both classical and modern statistical procedures. The
first fifteen years of S history are ably reviewed by Becker [1994], and there
is a thirty year history of the S language in Chambers [2008, Appendix A].
The statistical techniques that were implemented, for example in the White
Book [Chambers and Hastie, 1992], were considerably more up-to-date than
techniques typically found in SPSS or SAS. Moreover the S system was
build on a rich language, unlike Stata, which until recently just had a fairly
large number of isolated data manipulation and analysis commands. Statlib
started a valuable code exchange of public domain S programs.