The software the core software of R is actually quite lean.
Its functionality is divided into modular packages, so you don't
have to download and install a massive piece of software.
Whereas you can download
a very small piece of fundamental core, kind of
functions, and then add things on as you need them.
So it's graphics capabilities are very sophisticated and
give the user a lot of control over
how graphics are, are, are created, and in
my opinion are better than most stat packages.
It might even be the best for the mo- kind of a general purpose statistical package.
It's very useful for interactive work as I
said before, but it contains this powerful programming language.
For developing new tools,
so, it eases the transition from the user to the program.
And fundamentally, actually, for a language like this, is
that there is a very active and vibrant user community.
So the mailing lists at R-help and R-devel are very active.
There's many, posts per day, and there's also a
series on stack overflow where questions can be answered.
So, the user community is, is one of the most interesting aspects of R.
It's where all the R packages come from and it creates a lot
of kind of interesting features.