InformIT Articles and Sample Chapters

Rather than a topic in and of itself, Ajax is really an amalgamation of different technologies. Here are some places you can go for more information:

The heart of this technique is Javascript. Steve Holzner gives a great introduction to Essential JavaScript in a chapter from Inside Javascript (New Riders, 2002, ISBN 0735712859). He covers everything from the very basics to script errors and even touches on cross-browser issues.

As far as cross-browser issues go, Paul McFedries provides an excellent look in Cross-Browser Solutions: Detection and Generic Functions, covering not just how to figure out what browser it is, but also what kinds of functions you can perform in what browser. Very handy.

And while we're on the subject of Javascript, Andrew King's book, Speed Up Your Site: Web Site Optimization (New Riders, 2003, ISBN 0735713243) has great information on optimizing your Javascript for execution speed and download speed.

With all of the data you'll be moving around, you'll also want to have a good handle on using CSS to style and position your data on the page. To get you started, read The Basics of Cascading Style Sheets, from Matthew Pizzi and Zak Ruvalcaba's Macromedia Dreamweaver MX 2004 Unleashed (Sams, 2004, ISBN 0672326310).

If you already know the basics, you can move on to Molly Holzschlag's Integrated Web Design: Position This! CSS Positioning Demystified. Once you've got the basics of positioning down, you can move on to Shelly Brisbin's Layers and Positioning for information on content that adjusts its position based on the rest of the page, and William Weinman's Cascading Style Sheets (CSS): Absolute Positioning for information on content that doesn't.

Once you've already got your data, if it's in XML form, you'll need to deal with it just as you would in any other XML-based application. Check out the XML Reference Guide's sections on The Document Object Model, XSL Transformations, XPath, and REST. Meryl Evans also has a terrific section on Enhancing web page interaction in the Web Design Reference Guide.

Books and eBooks

Inside Javascript, by Steve Holzner (New Riders, 2002, ISBN 0735712859) gives you both the basics of working with Javascript and the advanced techniques you can use to really make your Ajax applications sing. (Start reading online)

Andrew King's book, Speed Up Your Site: Web Site Optimization (New Riders, 2003, ISBN 0735713243) tells you how to create Javascript applications that won't bog down. Considering that you'll be making network connections, you'll need all the help you can get here! (Start reading online)

DHTML and CSS for the World Wide Web, 2nd Edition: Visual QuickStart Guide by Jason Cranford Teague (Peachpit Press, 2001, ISBN 0-201-73084-7) may seem like an older idea, but DHTML -- the idea of using Javascript to dynamically affect the information on a web page is really the basis for Ajax. (Everything old is new again, I guess!) This book gently gives you a solid foundation from which to work. (Start reading online)

XML by Example, Second Edition by Benoît Marchal (Que, 2001, ISBN 0-7897-2504-5) demonstrates the use and manipulation of XML using Javascript, from the basics to the creation of an actual ecommerce application. (Start reading online)

Documentation and Implementations

Ajax is still extremely new, so there aren't any "formal specifications". You can, however, check out these links for some of the thinking behind this new technology:

• Wikipedia has an entry on Ajax that includes a discussion of the history, pros, and cons and links to other resources, including the seminal piece from Adaptive Path that coined the term and started the discussion.
• Alex Bosworth has a list of mistakes Ajax programmers make for you to avoid.
• Luke Wroblewski has a great discussion on AJAX & Interface Design, and also has links to more attendees of the Ajax Summit.
• FiftyFourEleven has a great list of working Ajax examples.
• Modern Method has released version 0.1 (note the decimal point's position) of SAJAX, a "Simple Ajax" toolkit.