This volume offers a gentle introduction to the world of references, object-oriented programming, and the use of Perl modules that form the backbone of any effective Perl program. Following the successful format of "Learning Perl", each chapter in the book is designed to be small enough to be read in just an hour or two. Each chapter ends with a series of exercises to help you practice what you've learned with answers in an appendix for your reference. Assuming just a rudimentary knowledge of Perl, this book explains how to effectively use both standard and object-oriented Perl modules, how to use namespaces and packages properly, and how to use references to build powerful data structures. In short, it covers everything that separates the Perl dabbler from the Perl programmer. Topics covered include: building larger programs with Perl; references and scoping; manipulating complex data structures; introduction to objects; advanced object topics; writing a distribution; essential testing; and contributing to CPAN.