Introduction

Although Ruby is an excellent tool for writing low-level scripts for system administration tasks, it is equally useful for writing end-user applications. And because graphical user interfaces (GUIs) are a must for modern end-user applications, you need to learn how to develop GUIs for Ruby. One of the benefits of Ruby programming that you've no doubt come to appreciate is that it enables rapid application development. In contrast to the time-consuming code-compile-test cycle of traditional programming languages, you can quickly make changes to your Ruby scripts to try out new ideas. This benefit becomes all the more evident when you start developing GUI applications with Ruby; it's both instructive and rewarding to build up the user interface incrementally, adding new elements and then re-running the program to see how the user interface has changed as a result.

You may already know that the standard Ruby source code distribution includes an interface to Tk, which is an established cross-platform GUI toolkit. If you peruse the Ruby Application Archive (RAA) however, you'll quickly discover that there is a large number of other GUI toolkit choices for use with Ruby (www.ruby-lang.org/en/raa.html). Why wouldn't you want to stick with Tk if it's the standard? Well, as you work through this chapter you'll learn about some of the considerations that might prompt you to look at alternatives. Like all software, these packages are in various stages of development: some are new and unstable, while others are older and quite robust, but most fall...