Book excerpt: This book is a comprehensive guide to utilizing and creating Ruby Gems. Coverage provides an enormous code library that will help developers improve their projects. It details 34 of the best and most useful Gems, including ones to speed up web applications, process credit card payments, produce PDF documents, read and update RSS feeds, and acquire real-time shipping prices from FedEx and UPS. Each of these also comes complete with actual use cases and code examples that readers can immediately use in their own projects. In addition, the book describes how readers can package and distribute their own Ruby Gems.