[Xylakant]

> At first sight, it seems hard to make a primary ordering of programming languages, because they focus on different areas (ease of use, speed of development, performance etc) and ordering those disjunct areas against each other seems to be impossible. However, it is still possible for a programming language to focus and excel on all those areas at the same time.

I disagree. There's more than ease of use, speed of development and performance to determine if a language is "better" suited to a problem than others. And they're all trade-offs to some point. So to excel at one means that you fall behind on others. Prolog is still used heavily in some areas since it's a natural fit to logic problems. It's just pure logic theory modeled in a programming language. It's a pityful language to solve most "real world" problems, but it excels at what it was made for. So is it "better" than ruby? I don't think so. Is it possible to write a language that models logic problems so nicely as Prolog and still keep the ease of use of ruby? I very much doubt that.