Concrete example: The Ruby community is very focussed on the Web, so there's Rails but they aren't really interested in scientific computing so there isn't a re

Concrete example: The Ruby community is very focussed on the Web, so there's Rails but they aren't really interested in scientific computing so there isn't a real equivalent to NumPy. I'd mod this up more if I could, because this is the best answer to the original question. The important thing is the community, not the language. Decide what your problem is, find the people who are working on that problem, and use whatever they use. The importance of community is the reason why the number of people who praise Lisp as a language is so much larger than the number who use Lisp every day: The Lisp community is small, unfocused, and arguably broken. Meanwhile, I work as a professional Drupal developer and am (god help me) gradually becoming an expert on PHP, but that has nothing to do with my nigh-nonexistent respect for PHP as a language. I do it because the Drupal community is large and growing larger, it includes as many noncoders as coders, and it's focused on building websites rather than obsessing over tools. The result seems to be that customers like using Drupal for their sites. Rails and the like are focused on making programmers feel empowered, but Drupal is focused on making site admins feel empowered.