It is not that hard to be fast compared to the standard implementation of Ruby, as this is dog slow. If you want to call it "freakisly fast", it should at least run as fast as Java or F#.

Sorry, but we've seen that Ruby doesn't scale. Not to mention that if you're working with a legacy database, you're in for a lot of work. Ruby's view is that the database merely persists their objects and has to follow their naming convention.

We have *not* seen that Ruby doesn't scale. That meme is pure BS.

What we have seen is Twitter struggling to cope with it's stellar growth rate. Frankly given their growth I'm amazed that they've only had 80 hours of downtime in the last year - that's remarkable. Twitter is the one example that's trotted out time and time again about how Ruby doesn't scale; I don't think I've heard of a single other example.

Several other Rails sites cope with fairly heavy traffic such as the 37signals sites and funnyordie.com.

Ruby as a language has no inbuilt support for databases. I'll give you the benefit of the doubt and assume that you are instead parroting criticisms about Rails' ActiveRecord ORM library. Unfortunately that criticism is largely ignorant - yes, there are naming conventions, but they can be overridden with configuration info to comply with just about any legacy database system. There's also a few other ORMs to choose from.

The "official" Ruby interpreters have indeed been rather slow when compared with most other dynamic languages. This new MacRuby 0.5 is much faster, and has not yet been optimised. It is too early to judge how it will compare with other languages like Perl or Python.

Whilst performance may be important, there is more to choosing a language than execution speed. Personally I find that I'm much more productive using Ruby which I only get to play with occasionally than Perl or JavaScript, the two languages I code in every day.