Practical Ruby Gems is a comprehensive guide to utilizing and creating Ruby Gems - ready-made Ruby code modules that can be easily added to Ruby and Rails projects. This book is ideal for Ruby programmers as well as web developers who use Rails and wish to extend the functionality of their projects.You'll get a prime selection of 34 of the best and most useful Gems, which makes up the core of this book. Each of these also comes complete with actual use cases and code examples that you can use immediately in your own projects. You'll learn how Ruby Gems can be used to * Validate credit cards. * Create graphical interfaces on multiple platforms. * Speed up Rails applications. * Develop lightweight web applications. * Use ActiveRecord to make databases easy. * Process RSS feeds. * Prevent spam using CAPTCHA. * Crop and scale images. * Tap into the same caching system that runs LiveJournal.com. And much, much more! You'll also learn how to package and distribute your own Ruby Gems. This lets you tap into powerful mechanisms for resolving dependencies. And the book takes a detailed look at how Gems differ between operating systems, so you'll be prepared whether your desktop runs OS X, Windows, or Linux. You'll also learn how you can share code more easily between projects, optionally sharing your contributions with the world!