S is a project of statistics research at Bell Labs since 1976. In 1998, S was the first statistical system to get the Software System Award, the top software award from the Association for Computing Machinery, ACM. S is a strongly functional, and object-oriented, highly extensible programming language, with a general interactive shell environment, extensive graphing abilities, a set of functions for mathematical and statistical manipulations and exploration of data sets, with more available in optional libraries/packages. It provides a variety of statistical (linear and nonlinear modeling, classical statistical tests, time series analysis, classification, clustering, ...) and graphical techniques. It can display graphical representations of data from a custom command line, and easily output well designed, publishable plots, including mathematical symbols and formulae where needed. It has yielded two more popular implementations, S-Plus (commercial) and R (Open Source).