I definitely agree with the article that once you learn a good set of "archetypal" languages, then most popular new languages become easier to learn. It's a wor

I definitely agree with the article that once you learn a good set of "archetypal" languages, then most popular new languages become easier to learn. It's a worthwhile exercise. But at the same time, there are some deeply weird languages out there. These contain some absolutely fascinating ideas. And if you follow the advice in the article to learn "every" language, then these languages will still surprise and perplex you. - If you go deep enough in Haskell that you stop being confused by monads and start being confused by "free monad interpreters", then Haskell will provide you with a nearly endless source of complex, powerful abstractions—more than enough for any 10 other research languages. - Mozart (http://mozart.github.io/ http://mozart.github.io/) is a concurrent logic language with a constraint solver. Even if you're familiar with Prolog and Erlang, this one's going to blow your mind. - Coq (https://coq.inria.fr/ https://coq.inria.fr/) is a language for formally proving the correctness of the things you compute. (You typically also write your programs in Coq.) There are also other, newer languages in this space. These languages have a steep learning curve, and they're challenging to work in, but they're extremely interesting. Learning exotic programming languages is fun, and it means that you'll rarely be surprised by any new popular language. But despite this article's suggestion to "learn every language", you won't run out of strange new languages any time soon.