Mozilla is not just a browser. Mozilla is also a framework that allows developers to create cross-platform applications. This framework is made up of JavaScript, CSS (Cascading Style Sheets), and Mozilla's XUL (XML-based User-interface Language) as well as the Gecko rendering engine, XBL (eXtensible Binding Language), XPCOM (Mozilla's component model), and several other components. This volume explains how applications are created with Mozilla and provides step-by-step information about how you can create your own programs using Mozilla's powerful cross-platform development framework. This book also shows examples of many different types of existing applications to demonstrate some of the possibilities of Mozilla application development. One of Mozilla's biggest advantages for a developer is that Mozilla-based applications are cross-platform, meaning programs work the same on Windows as they do on Linux or the Mac OS. Working through the book, you are introduced to the Mozilla development environment and after installing Mozilla, you quickly learn to create simple applications. After the initial satisfaction of developing your own portable applications, the book branches into topics on modular development and packaging your application. In order to build more complex applications, coverage of XUL, JavaScript, and CSS allow you to discover how to customize and build out your application shell. The second half of the book explores more advanced topics including UI enhancement, localization, and remote distribution. Mozilla 1.0 was released on June 5th, 2002, after more than four years of development as an open source project. This book has been written so that all of the information and examples will work with this release and any of the 1.0.x maintenance releases. In addition to Netscape's Mozilla-based browsers (Netscape 6.x and 7.x), the Mozilla framework has been used to create other browsers such as Galeon and Chimera, and chat clients such as ChatZilla and JabberZilla. Developers have also used Mozilla to create games, development tools, browser enhancements, as well as all sorts of other types of applications.