Mark Ryall wrote:
> I suppose i meant just to say that performance is not a factor i'd use to
> choose between python and ruby - i'd pick the one that allowed me to write
> code that more clearly expressed my intentions to its most important
> audience - myself sometime in the future and other unsuspecting developers.

It might not be your choice but there *are* those who *will* use it as a 
deciding factor. And that is enough justification for the efforts of the 
Ruby 1.9, jRuby and Rubinius teams' efforts to make Ruby's performance 
competitive with that of the other major scripting languages.

[snip]

> Most of the time, choosing a language based on it having the fastest runtime
> environment is probably very early premature optimisation.

Those on this list who know me probably realize that "premature 
optimisation" is a concept I find difficult to grasp. I'm very familiar 
with the philosophies of the great gurus Dijkstra, Hoare, Milner, Knuth, 
etc. -- I "grew up" with them, so to speak. And I don't think there's 
*anything* in their writings that justifies inattention to performance 
concerns at *any* stage in the software development cycle, *including* 
selection of a programming language!

In fact, Dijkstra, in _A Discipline of Programming_, explicitly calls 
out that one must pay attention to the twin concerns of correctness and 
efficiency. And, while the hardware is orders of magnitudes faster and 
cheaper than it was when Dijkstra wrote that, throwing hardware at an 
inefficient design is still not economically viable in the long run and 
probably never will be.