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:
Site: http://research.microsoft.com/fsharp/
Ocaml with meta-programming.
Site: http://www.metaocaml.org/
Ocaml extended with join-calculus constructs for distributed programming.
Site: http://jocaml.inria.fr/
G'Caml is a variant of O'Caml compiler which extends ML parametric polymorphism to non-parametric one, called extensional polymorphism
Site: http://web.yl.is.s.u-tokyo.ac.jp/~furuse/gcaml/
Standard ML of New Jersey (abbreviated SML/NJ) is a compiler for the Standard ML '97 programming language with associated libraries, tools, and documentation.
Site: http://www.smlnj.org/
MLton is an open-source, whole-program, optimizing Standard ML compiler.
Site: http://www.mlton.org/
Alice ML is a functional programming language based on Standard ML, extended with rich support for concurrent, distributed, and constraint programming.
Site: http://www.ps.uni-sb.de/alice/
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.
Site: http://www.itu.dk/~sestoft/mosml.html