Bulletproof Ajax is a systematic exposition of how to use what is termed the Ajax Toolkit, specifically the XMLHttpRequest object, along with a server-side language such as PHP, JavaScript, cascading style sheets (CSS), and Extensible Markup Language (XML). The focus throughout the text is on building applications that will degrade gracefully, for example, by continuing to display critical content even if Ajax features are not fully supported. Similarly, the author demonstrates an efficient and effective way to develop Web sites to facilitate enhancement and maintenance. The author does not ignore what he calls challenges for Ajax, including issues such as dependence on nonstandard features like innerHTML.

Nine chapters make up the book. The first four, “What Is Ajax,” “JavaScript and the Document Object Model,” “XMLHttpRequest,” and “Data Formats,” cover the basics. The next chapter, “Hijax,” demonstrates the integration of the tools, including CSS, and how the Ajax approach means that forms can be handled without refreshing the whole page. Hijax is the author’s name for his approach. Chapters 6 and 7, “Ajax Challenges” and “Ajax and Accessibility,” discuss issues such as bookmarking, the back button, and accessibility concerns. Chapter 8, “Putting It All Together,” fulfills the promise of its name by explaining a bookshop application. The last chapter, “The Future of Ajax,” includes useful references. The book does an excellent job of presenting code, includes many illustrations, and uses typography that is very easy to read. There is also a companion Web site (http://bulletproofajax.com).

My only concern with this book relates to the author’s specification of audience. I place myself in the set of “server-side programmers who want to learn about Ajax,” as well as “programmer[s] accustomed to creating complex objects,” but the author says the book is not for me. However, I found it valuable and will recommend it to my peers. In contrast, Keith recommends the book for front-end developers familiar with semantic markup and CSS, and “perhaps even some rudimentary DOM scripting.” This group could benefit from reading this text, though experience in scripting certainly would help. The book would help front-end developers talk with other members of their teams to better produce “bulletproof” applications.