I think that the reality of modern scala is that, while there is in no way a unified use of the language, the way to use Scala is in its own, intermediate location. Libraries have big gains from the most exotic features that make it be closer to FP, like higher kinded types. while business code tends to look more like java with case classes and algebraic data types. The difficult part is the fuzzy middle.

Another important part of adoption is that Scala's strengths lie in a few good libraries that underpin some great use cases. For instance, using Scalding or Spark as ways to do big data, or building other kinds of distributed systems on top of Akka. For other uses, like writing simple CRUD services, there are many options, and almost all of them are bad, which is why treating the language as just a better Java just doesn't fly.

http://elixir-lang.org/

And yes, it's quite fun (and mind-bending at the same time, in a good way).

/s

Disclaimer: complete Elixir noob

It's used by a few big names (Bayard Rock, Tachyus, Jet.com, BlueMountain Capital, Microsoft Research, etc.) and it looks to be gaining more mainstream acceptance.

I predict we'll see more and more of that, but never a great breakthrough:

- appreciation of pure functions and immutability - optional typing even in Python - Garbage collection (mainstream since Java) - higher order functions - algebraic data types (in Scala, sort-of possible in C++ boost, and even in protobuf) - etc

But those that read my Java, C# and C++14 code, better know their way around lambda calculus.