I think anything that has a good standard library is pretty productive. The killer of productivity is when you need some core functionality and have to write it yourself. Like a linked list or map, etc...
Ofcause; sometimes just because you can write something in Java using a sockets api quicker than C++ doesn't mean by the end of the project it was the more productive solution.
That begs the question: what is a good standard library? One with lots of features? One that is well-written and efficient? One that is easy to use?
For example, C++ has a pretty large standard library, with loads of features. But due to backwards compatibility with C, its naming conventions are rather user unfriendly and inconsistent (all hail the Great Consonant!)...
I don't think the standard library is a deciding factor in here. I think it's more about
expressiveness.
For example, I'm not sure whether JavaScript's (Node.js') stdlib has a tenth of features that C++/Java stdlibs have. That's not to say it's standard library is lacking, because most of the important features are actually
inherent to the language itself.
When you look at it that way, you could almost conclude that C++ and Java are
lacking in contrast to JavaScript, and that their standard libraries are merely compensations that still don't meet the greatness of JavaScript's inherent expressiveness.
Edited by Yannbane, 06 March 2013 - 08:43 AM.