Pyret is similar to the ML family in many ways. Some would say Pyret's syntax is an improvement over that of OCaml. (Others might not.) A critical difference

Pyret is similar to the ML family in many ways. Some would say Pyret's syntax is an improvement over that of OCaml. (Others might not.) A critical difference is that Pyret does not force static typing. The type-checker is optional, so beginning students, in particular, do not need to deal with the overhead of type errors and the vagaries of type inference. But Pyret's design, and pedagogy, aim to push students towards an ML style of programming with ML-like types (e.g., the language does not have untagged unions). In fact, type inference in Pyret is done not from the code but from the tests the programmer has written. This is a very different philosophy of not just inference but program development.