'Ajax: The Definitive Guide' certainly is definitive. With 950+ pages of content, this book doesn't know the word brevity. Spanning 23 chapters and 4 appendixes, this book covers everything you would want to know about AJAX. From its history to how it's grown to where things are today and in the future, this text is very complete. If you are new to AJAX and want to learn how to use it in an extensive way, this is a great resource. My only qualm with this book is that I feel it is just TOO big in size. A 'Learning AJAX' book at around 200-300 pages would be a great companion book to have on the side, then switching over to this bible-size book would be a good transition. Overall this is written well, laid out in detail, and typical O'Reilly quality.

***** RECOMMENDED

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There is a LOT of code in this 950 page book. I guess there is something here for everyone because there is code not directly related to Ajax but is directed to HTML structure or CSS presentational aspects or to frameworks that may include Ajax conveniences.

In fact, the amount of code may interfere with the author's object of appealing to two very different types of people with this book: Web developers and project managers looking for a high-level view. Except for some intro chapters and the odd breather between 10-15 page code listings, I don't think any project managers *I* have worked with would extract much from the book.

The book has 4 sections:
Part 1 - Ajax Fundamentals: the basic technologies that could form the core of a typical Ajax application.

Part 2 - Ajax Foundations: approaches to standards-compliant structure, separation of the presentational layer and client-side behaviors. Code code code!

Part 3 - Ajax in Applications: describes the specific implementations of these technologies into Web applications. More code!

Part 4 - Wrapping Up: tips on optimization.

In addition, there are some reference appendices on XML and XSLT; on JavaScript frameworks; on Ajax implementation risks; and most interestingly, a catalog of freely available Web service APIs.

One thing I did not like about the code listings was the use of Prototype style $() function syntax. This means when I see something like:
var titleText = $('title').firstChild;
I had to check whether .firstChild was a reference to a Prototype object or a reference to the standard DOM object. If the standard object, it would have been a whole lot clear just to have written document.getElementById().

The book index is actually pretty good. With 950 pages stuffed with content, you will probably be thankful for that!
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