Ajax - what is this?

Does "Web 2.0" mean anything more than the name of a conference yet? I don't like to admit it, but it's starting to. When people say "Web 2.0" now, I have some idea what they mean. And the fact that I both despise the phrase and understand it is the surest proof that it has started to mean something.

One ingredient of its meaning is certainly Ajax, which I can still only just bear to use without scare quotes. Basically, what "Ajax" means is "Javascript now works." And that in turn means that web-based applications can now be made to work much more like desktop ones.

As you read this, a whole new generation of software is being written to take advantage of Ajax. There hasn't been such a wave of new applications since microcomputers first appeared. Even Microsoft sees it, but it's too late for them to do anything more than leak "internal" documents designed to give the impression they're on top of this new trend.

In fact the new generation of software is being written way too fast for Microsoft even to channel it, let alone write their own in house. Their only hope now is to buy all the best Ajax startups before Google does. And even that's going to be hard, because Google has as big a head start in buying microstartups as it did in search a few years ago. After all, Google Maps, the canonical Ajax application, was the result of a startup they bought.

So ironically the original description of the Web 2.0 conference turned out to be partially right: web-based applications are a big component of Web 2.0. But I'm convinced they got this right by accident. The Ajax boom didn't start till early 2005, when Google Maps appeared and the term "Ajax" was coined.

Think of AJAX as the second coming out party for JavaScript and DHTML. Second coming out party ? JavaScript is at least 10 years old and DHTML is not much further behind. What is going on ? What is going on is that Microsoft, through its dominant Web browser market share has effectively halted all progress on DHTML and standards based web development for 5-7 years. The means was simple. All DHTML development projects were halted at 1 Microsoft Way. All feature and function updates to IE, including meeting promises to fully implement W3C standards, were halted for 5-6 years. In effect all new and promising technology for the Web were put on hold because IE has had 90%++ market share so Redmond could act as a gatekeeper on all client-side browser technology.

And as gatekeeper, Microsoft has said no no no to everything: SVG, SMIL, XForms, JavaScript 2.0 and E4X, CSS 2.1 and 3.0, JPEG2000, DOM 3.0 + Rationalization and many other Web technologies. See details on Microsoft's belligerence against the Web here.

The key to AJAX and its advanced DHTML is to load enough JavaScript on a web page so that it can manage most if not all the events that occur there. This takes shape in using some of the following methods:

1)use JavaScripts for validations and redirection within forms using 'on events';

2)use pre built JavaScript GUI components like menus, calendars, calculators, tabs and grids;

3)use CSV or XML staging or caches for data interactions including possible offline tasks;

4)use XMLHTTP or XML-RPC or SOAP for hotspot or partial page refreshes and asynch ops;

5)use iFrames and CSS div-Windows as portals for multiple landing spots on a page.It is these techniques and others like it that are at the core of JavaScript programming methods now known as AJAX-Asynchchronous JavaScript and XML. Think of AJAX as starting to release the full potential of JavaScript on the Web.