[R] What makes R different from other programming languages?

[johannes rara]

My intention is to give a presentation about R programming language
for software developers. I would like to ask, what are the things that
make R different from other programming languages? What are the
specific cases where Java/C#/Python developer might say "Wow, that was
neat!"? What are the things that are easy in R, but very difficult in
other programming languages (like Java)?

Thanks,
-J