A fairly large collection of freeware S-Plus code can be found on the statlib Web server. Moreover, S-Plus seems to be a popular choice among applied statisticians for the development of new statistical algorithms. S-Plus functions are usually provided by authors, free of charge. Available through the MathSoft Seattle office. R is collaborative project whose purpose is to develop a freeware system for statistical computation and graphics.
R only provides a command interface and a graphical interface.
Additionally, it lacks quite a bit of statistical functionality of its commercial counterpart. However, R is an ongoing project and its functionality increases steadily. At some point in the future the Research and Statistical Support Office will support a UNIX version of R on Sol.