I've used Clojure in a few cases and I totally adore the simplicity of its Lisp syntax as opposed to the baroquesque abomination that is Scala. However, lack of strong typing is sorely felt. I 've done a little playground-style OCaml coding and the feeling you get with OCaml is that once your program compiles, it most likely also runs correctly. Is a Lisp language with strong typing for the Java ecosystem too much to ask? Apparently it is or else we would have had it by now.

Theres the new clojure.spec[1] in 1.9 and core.typed[2] adds an optional type system as well.

[1]: http://clojure.org/about/spec [1]: https://github.com/clojure/core.typed

The REPL-driven development of Lisps makes types not as important because everything is interactively tested as you write it. Having an optional type system makes it much easier to start with dynamic types and gradually add type annotations as your architecture stabilizes.