It's practically the holy grail: applications that run in web browsers, use standard web technologies, yet have the richness, responsiveness, and usability of today's best desktop applications. But this quest has a destination: Ajax. If you've used Gmail, or Google Maps, or Flickr, you've seen Ajax at work. If you read Ajax in Action, you can put it to work, too. Ajax requires you to think about web development in very different ways. Forget the page-based metaphor; start thinking about design patterns, refactoring, and managing client codebases. Dave Crane and Eric Pascarello cover all that, and much more, including architecture, security, and performance. Their sample applications prove you can use Ajax for both large and small projects - and add value to existing web applications in surprising ways.