I am primarily a .NET developer and while this book focuses on the use of AJAX with PHP that was hardly a factor for me. I was able to build my own AJAX library based on the examples within and use it in my current .NET projects. Something I prefer rather than using the AJAX libraries Microsoft provides. This book is of perfect depth and is quite efficient. I recommend this book.

In most cases the book provides examples of PHP code. The title of this book is misleading. If you want to learn the AJAX from the javascript perspective do not buy this book. I was upset by the misleading title of this book and feel riped off by the author who claims that he devotes the contents to AJAX and javascript.

This is a great book for someone with a good understanding of HTML and an intermediate understanding of JavaScript. Some of the examples are set up to run on a PHP server as well. Joshua talks about some common pitfalls of AJAX development as well as methods of avoiding them and considerations of real-world applications. He breaks down some of the more complicated concepts very well, and gives straight forward explanations of browser compatibility. A great reference and guide to an exciting technology.

Understanding AJAX is a very in-depth look at some of the technologies used in modern web design. In reading this book, you will come to understand the pros and cons of using AJAX in a web site and exactly what happens between the browser and the web server.

You will get a sense of what can and can't be done using AJAX and how to get around the problems caused by the many web browser clients in use at this time. You will also come to understand how to make the user's browser do much of the work that your server used to do. Understanding AJAX also dives into the usage of many open source script libraries to make coding a modern website much easier. From adding DHTML effects to using a single page for your entire site, you will get a feel for what is possible.

This book is not for the beginner. You should have at least a moderate knowledge of HTML and Javascript, and at least a beginning understanding of a server side web scripting language (PHP is the primary language used in the book). This is not a cookbook, but does contain many code examples later in the book, including a login system and an ajax trouble ticket system.

I have been using Joshua's HTML_AJAX php/ajax library for over half a year, but was still able to learn quite a bit from this book.

I would recommend this book to any web developer who wants a thorough understanding of AJAX and how it can be used.

Eichorn's narrative teaches Ajax from scratch. But he writes for a reader already well versed in Web programming. This implies familiarity with HTML and how a Web server responds to http requests. XML knowledge is also needed. Along with how XML data is parsed, by a DOM parser or by XSLT. Actually, for the latter, the book correctly points out its sheer complexity. One nice piece of advice it offers is simply to warn you of this. Oh, knowing JavaScript and PHP also helps. Since JavaScript is the main scripting language on most current browsers. So if you want client side functionality beyond HTML, JavaScript is often the way to go, whether or not you use Ajax.

The main thrust of the book is in showing how Ajax works. An ingenious combination of client and server side functionalities. This however has led to the varied requirements described above. The book also warns that Ajax development can bring problems of its own. A useful cautionary note, in light of the recent hype about Ajax. One issue is that using Ajax to alter an existing web site can lead to unexpected changes in usability, and in the very design of the site. Plus, Ajax's production of an application-like feel to the client side on the browser can lead to complex debugging. You don't get those neat extra features at zero cost!