For all the shiny newness of the interest, none of the technologies
around since the mid-90s. It’s also dependent on the Document Object
Model; standard web technologies such as CSS, XHTML, and XML; and the
XMLHttpRequest object, all of which
were introduced years before the term Ajax was coined.
What is new is the fact that a concept was introduced for a type of development, coinciding with newer browsers, all of which enable the necessary functionality. In other words, the time was ready for the technology; all that was needed was someone to notice, package it, and promote its use. That someone was Jesse James Garrett in his publication, “Ajax: A New Approach to Web Applications” (at http://www.adaptivepath.com/publications/essays/archives/000385.php).
Where the Ajax examples in this chapter differ from examples in previous chapters is that Ajax does require a server component. Ruby is a popular choice of programming language for Ajax development, but any server-side language that can process the specialized Ajax requests will work. The examples in this chapter use PHP, primarily because of all the languages, it’s ...