Content Summary : As far as web interface design techniques are concerned, AJAX is defi nitely the way to go. So what JavaScript library worth its salt these days wouldn't want to include a component dedicated to this extremely useful and versatile method of client/server communication? The term AJAX has been part of the mainstream development community's vocabulary since early 2005 (with the advent of Google Mail). Although some of the key components that AJAX consists of, such as the XMLHttp object, have been around for much longer (almost a decade in fact). The goal of asynchronously loading additional data after a web page has rendered is also not a new concept or requirement. Yet AJAX reinvented existing technologies as something new and exciting, and paved the way to a better, more attractive, and interactive web (sometimes referred to loosely as web 2.0) where web applications feel much more like desktop applications. AJAX can also perhaps be viewed as the godfather of many modern JavaScript libraries. Maybe it wasn't the sole motivating factor behind the growing plethora of available libraries, but it was certainly highly infl uential and orchestral in their creation and was at least partly responsible for the fi rst wave of modern, class-based JavaScript libraries. Like many other cornerstone web techniques developed over the years, AJAX was (and still is) implemented in entirely different ways by different browsers. I don't know if developers just fi nally had enough of dealing with these issues.