[mumblemumble]

When you're doing something like writing your own routine for calculating fibonacci numbers, perhaps. But that's not the kind of optimization that's likely to be significant to most developers writing business applications.

I would also argue that the ubiquity of things like BLAS wrappers largely blurs these lines. For example, one of the big reasons I choose Python over Java (my company's primary language) for my work is that, thanks to numpy, Python absolutely smokes Java at crunching numbers, for my purposes. This despite Java being a compiled static language and Python being an interpreted dynamic language.