Camlp4 is a software system for writing extensible parsers for programming
languages. It provides a set of OCaml libraries that are used to define
grammars as well as loadable syntax extensions of such grammars. Camlp4 stands
for Caml Preprocessor and Pretty-Printer and one of its most important
applications is the definition of domain-specific extensions of the syntax of
OCaml.

This package is obsolete and no longer supported by OCaml 4.09 and over.
Users should switch to the new PPX infrastructure or use Camlp5.