show modules your program loads
Devel::TraceUse can analyze a program to see which part used which module. 

Command-line usage:

$ perl -d:TraceUse myprog.pl

will display a tree of the modules ultimately used to run your
program. (It also runs your program all the way through to the end with
a small startup cost.)

Maintainer: The OpenBSD ports mailing-list <ports@openbsd.org>

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