R has frequently been a source of inspiration for me. (I mention his briefly here:
http://mvz.so/articles/lend-a-hand-to-science.html) It appears, to me, as an example of a tool that has done and continues to do its job, for the benefit of all mankind. This isn't to say it couldn't have been done better, but I'm consistently impressed by the wide-ranging use and love that R finds in so many fields, and by the breadth of people who use it, most of whom would never call themselves programmers. I can't figure out what exactly R got right, but I often think it has something to do with the fact that it was created by someone who called himself a statistician, not a programmer.