Ten years ago, I wrote the first edition of Learning Perl. In the intervening years, Perl itself has grown substantially from a "cool" scripting language used primarily by Unix system administrators to a robust object-oriented programming language that runs on practically every computing platform known to mankind.

Throughout its three editions, Learning Perl remained the same size (about 300 pages) and continued to cover much of the same material to remain compact and accessible to the beginning programmer. But there is much more to learn about Perl than there was ten years ago.

This book may be entitled Learning Perl Objects, References, and Modules, but I like to think of it as just Learning More Perl. This is the book that picks up where Learning Perl leaves off. It shows how to use Perl to write larger programs.

As in Learning Perl, each chapter in this book is designed to be small enough to read in just an hour or two. Each chapter ends with a series of exercises to help you practice what you've just learned, with the answers in the Appendix for your reference. And like Learning Perl, the material in this book was developed for a teaching environment and used in that setting, including for our own use at Stonehenge Consulting Services as we present onsite and open-enrollment trainings.

You don't have to be a Unix guru, or even a Unix user, to benefit from this book. Unless otherwise noted, everything in this book applies equally well to Windows ActivePerl from ActiveState, and all other modern implementations of Perl. To use this book, you just need to be familiar with the material in Learning Perl and have the ambition to go further.