Yesterday I coded 2 non-trivial apps in Scala, a total of 192 lines of code (excluding blanks and comments).
Scala is a very elegant programming language, and I'll probably do more with it someday. Alas, it's not a good fit for my present needs. But if nothing else, I can confidently say my physics library works with Scala.
Now if you believe semicolons are uncool and curly braces limit your productivity, then you're going to love the language I'm working in today:
I've encountered LISP a few times before. The last time was in 1987, when my CompSci 143A professor decided it would be easier to teach compiler design if all the examples and projects were in Scheme. Never mind that none of his students had heard of Scheme. (He might as well have lectured in Mongolian!) Luckily, I'd studied a LISP dialect (I forget which one) as an undergrad, so I started a step higher on the learning curve than most of my peers.
Languages in the LISP family (like Scheme and Clojure) have a very different syntax from block-structured languages like C++ and JavaScript. It's like the difference between football and chess. Throw in an unfamiliar build tool (Leiningen) and I expect I'm in for an adventure.
If anyone calls, tell them I'm busy matching parentheses!