Description:

Camlp5 is a Pre-Processor-Pretty-Printer for Objective Caml. It offers
tools for syntax (grammars) and the ability to modify the concrete
syntax of the language (quotations, syntax extensions).

Camlp5 can parse normal Ocaml concrete syntax or any other
user-definable syntax. As an example, an alternative syntax is
provided, named revised, because it tries to fix some small problems
of the normal syntax.

Camlp5 can pretty print the normal Ocaml concrete syntax or the
revised one. It is therefore always possible to have a version of your
sources compilable by the Objective Caml compiler without
preprocessing.