Had to add this because I thought it was fairly obvious, but all the other Scala mentions were either snarky or seemed to miss the core point of the title of the post : "What languages fix"
Scala : functional programming without leaving the JVM
Because enterprises have spent a decade or so building up JVM expertise in the form of Java.
Scala is really a multi-paradigm language, and that is arguably one of its major selling points. While you can use it exclusively for functional programming if you wish, object-oriented and imperative programming are equal citizens.
Scala is much more than a functional language, its more like Java done much better, not all of its useful features are functional. Maybe you meant clojure?
Scala : functional programming without leaving the JVM
Because enterprises have spent a decade or so building up JVM expertise in the form of Java.