This page explains differences and similarities between Ocaml and some related languages.
Implementation of an Ocaml-like language for Microsoft's .NET platform. While very similar, it has some important differences:
Ocaml with meta-programming.
Ocaml extended with join-calculus constructs for distributed programming.
G'Caml is a variant of O'Caml compiler which extends ML parametric polymorphism to non-parametric one, called extensional polymorphism
Standard ML of New Jersey (abbreviated SML/NJ) is a compiler for the Standard ML '97 programming language with associated libraries, tools, and documentation.
MLton is an open-source, whole-program, optimizing Standard ML compiler.
Alice ML is a functional programming language based on Standard ML, extended with rich support for concurrent, distributed, and constraint programming.
Moscow ML is a light-weight implementation of Standard ML (SML), a strict functional language widely used in teaching and research.
It is partly derived from the Caml Light.