<i>&gt; Also OCaml is highly productive</i><p>More precisely, OCaml allows me to refactor my code very quickly, finding almost all mistakes even before any testsuite runs.<p>This is possible due to a combination of language features which only few languages have (notably, Haskell, SML and F#).<p>Not sure how this goes into total productivity, but this acceleration in development speed is something that no number of frameworks or libraries can match up.