Perl 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, typicaly ppport.h, written by this module attempts
to bring some of the newer Perl 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.

Why you should use ppport.h in modern code: so that your code will work with
the widest range of Perl interpreters possible, without significant additional
work.

Why you should attempt older code to fully use ppport.h: because the reduced
pollution of newer Perl versions is an important thing, so important that the
old polluting ways of original Perl modules will not be supported very far into
the future, and your module will almost certainly break! By adapting to it now,
you'll gain compatibility and a sense of having done the electronic ecology
some good.

WWW: http://search.cpan.org/dist/Devel-PPPort/