OCaml is an advanced programming language based on the ML family. It supports functional, imperative and object-oriented programming style. The code can either be compiled into bytecode or native for several platforms. There is much work in the compiler which, as a consequence, is highly efficient (see http://www.bagley.org/~doug/shootout/).
Official website: http://www.ocaml.org
Ressources: http://pauillac.inria.fr/caml