In addition to @noelwelsh's reply, I want to add that we are very much working on a type system (we have a working internal prototype). We are also working on a

In addition to @noelwelsh's reply, I want to add that we are very much working on a type system (we have a working internal prototype). We are also working on a very different kind of type inference, unlike Hindley-Milner. For us, it's important that the error story be as good as the "proper functioning" story, which is why we haven't released these. But it does mean that in the near future, people will be able to program in the typed language starting whenever they want, including from the very beginning. (And then we can do some experiments, too!)