frej

Sbt is actually worse than dune+opam .

Ocaml has type inference globally so you are not required to spray type annotations at everything.

But Scala does have type directed lookup (type classes/ implicits).

Both have the curse of implementation/typing choices that stops you from doing the actual job ;)

Second what Sun choose to implement was a smaller subset and not that close to Featherweight Java/pizza compiler. It was only generics, not first class functions at the time, nor algebraic types/pattern matching.