> From the outside, I didn't see any evidence of this. The people who were better and more experienced engineers tended to produce more, better, and faster. I s

> From the outside, I didn't see any evidence of this. The people who were better and more experienced engineers tended to produce more, better, and faster. I saw that they were happier using the tools of choice. As far as I could tell the supposed extra productivity over Rails or some other modern framework for the task at hand was largely illusory. I don’t think the claim is that one has to use those older technologies exclusively. I read the GP’s comment as that the knowledge one gains by learning those older technologies gives one more tools in their bag when using modern technology. > The primary gain from Lisp and similar is, in my experience, not that it's useful for writing software. It's that learning a different approach teaches you new ways to attack problems. Sometimes those are useful. Exactly. An example: trying to learn functional programming? Erlang will force one into that mindset. It is natural to spot mapping, folding, flattening in any other language later on. Working with local data, or state machines becomes a habit because there’s no other way of doing things in Erlang. That knowledge is directly applicable in any other language.