R

R is a language and environment which is a dialect of the S language. R provides excellent facilities for explanatory data analysis via an extensive collection of graphical functions.

Moreover all standard statistical analyses as well as many recent developments are available in built-in packages or in add-on packages. At the moment more than 300 add-on packages are available.

Go to the home page of the R project to find out more (home page of the R project).

Admittedly R has a steep learning curves and it can be rather time consuming to get to appreciate the way it works. But we would like to encourage everybody keen on doing data analysis to try learning it. It is worth the effort!