Any Turing-complete language can do any computational task that is computable by Turing-complete languages, so by that criteria every language is the same. Obvi

Any Turing-complete language can do any computational task that is computable by Turing-complete languages, so by that criteria every language is the same. Obviously, in practice they are not. That's a straw man, I didn't use that as a criteria. PHP and Ruby are both object oriented imperative scripting languages that are commonly used for connecting to a DB and spitting out markup See that? That's me describing specific qualities of the languages that make them similar. Of course, you could use Ruby or PHP to write a graphics engine (in fact, I have done so with Ruby), but that is not a common use case. Most of the time, Ruby and PHP are used to solve the same set of problems: scripting server-side logic for the web. Consensus of whom? The internet? The programming community? That's why I used the "nebulous" qualifier. I'm not saying it's a fact, but it's a pretty popular sentiment which is about as solid as it gets with regard to matters of taste. Yes, PHP and Ruby are different, but most of the time they are used to do the same thing.