Modules and Libraries
Perl5 provides you with a number of modules and extensions that contain packages (classes). Using them simplifies and enhances the process of creating new Perl programs. These modules are akin to C++ class libraries, in many ways, but are still simply Perl packages, in the end. The older Perl4 libraries and packages are, in most cases, still available, but many have been rewritten as modules where appropriate.
Working with Perl modules is the basis of this book. I supply very little code that is new. The idea is that, once something has been developed to perform a task, you should make use of it, or you're wasting your precious time.
TIP:
"Don't reinvent the wheel." Although this advice sounds trite, it's important to the continued development of Perl5 as a viable object-oriented language. The authors of the many useful Perl5 modules have spent a lot of time and effort to provide their modules. Because this voluntary contribution is the foundation of the Perl development effort, it should be nurtured and utilized to the fullest extent. I suggest that you try to utilize these modules and help out where you can, by reporting bugs and providing fixes and enhancements back to the author where appropriate.