Jesse James Garrett has a great new piece up on the Adaptive Path website describing the technology behind the newest generation of web applications. Instead of providing the standard click-and-wait approach to doing things on the web, companies like Google, Ludicorp, and Amazon are implementing apps built on a foundation of asynchronous communication, JavaScript, and XML (hence the nickname “Ajax”); the combination allows the apps to behave more like desktop applications, with fast response times (like being able to move a map around in real time) and a ton of activity on the client side (like autocompleting entries into text fields, or an entire interface implemented at the client like in Gmail). The idea is catching on enough to show up on personal sites, as well — for example, the search functions on Anil’s and Dunstan’s weblogs return results as you type.

Jesse’s right — Ajax is a revolutionary step in the evolution of the web, and it’s certainly going to be fun watching how developers use it to create the kind of applications that make users stop noticing the difference between the web and the desktop. Google Maps and Gmail are already doing this; as soon as there’s an Ajax implementation that’s easy for the lone developer to install and use, the sky’s truly the limit.