Perl's API has changed over time, gaining new features, new functions,
increasing its flexibility, and reducing the impact on the C
namespace environment (reduced pollution). The header file written
by this module, typically ppport.h, attempts to bring some of the
newer Perl API features to older versions of Perl, so that you can
worry less about keeping track of old releases, but users can still
reap the benefit.

Devel::PPPort contains a single function, called WriteFile. Its
only purpose is to write the ppport.h C header file. This file
contains a series of macros and, if explicitly requested, functions
that allow XS modules to be built using older versions of Perl.
Currently, Perl versions from 5.003 to 5.10.0 are supported.

This module is used by h2xs to write the file ppport.h.