Do you know about Ajax? (Not the detergent.) Ajax enables developers to put together Web applications that rival the best desktop applications.

An excerpt from a CNET report by Martin LaMonica, “AJAX gives software a fresh look“:

Over the years, desktop applications tied to a specific operating system have become entrenched as the main way to work on a computer. AJAX, a set of development techniques standardized over the past eight years, could change all that by bringing more sophisticated interfaces to Web applications. With that, backers are hoping it can open a crack in the dominance of desktop software like Microsoft’s Office, the undisputed market leader.

“This is a space that’s crying out for innovation,” said Scott Dietzen, president of messaging start-up Zimbra. “At this point, there isn’t a company that’s up to challenging Microsoft. But we’re out to change that.”

Why should you care about Ajax? You’ll have plenty more alternatives to desktop applications such as Outlook, and eventually migrate away from vulnerable (and costly) applications such as Microsoft Office. Ajax-developed applications work on the server side, with standard Web browsers and require little or no support and no installation of software or plug-ins on your computer. If you use Web applications like Webmail, or a blogging tool such as Blogger or WordPress, you already know the advantages of using a free Web application. Imagine these Web applications on steroids.

At some point in the future, due to Ajax, you will probably use more Web applications to get things done — such as retrieve and store email, collaborate with colleagues on documents, keep track of research, update databases, schedule your calendar, and so on — without the need for desktop (read: Microsoft) applications.

Others agree. Richard MacManus, in “The Web-based Office will have its day” in Web 2.0 Explorer, writes:

Once the current crop of alpha and beta web-based office products reach a level of maturity, they will be ready to challenge Microsoft for the minds and pockets of consumers.

One of the many examples of how Ajax Web applications can change everything is Writely, a free word processor (still in beta testing as of this writing) you can use from your browser without installing or downloading anything.

For the most succinct explanation of Ajax, here’s an excerpt of an essay titled “Ajax: A New Approach to Web Applications” by Jesse James Garrett of Adaptive Path and the author of the widely-referenced book The Elements of User Experience.

Desktop applications have a richness and responsiveness that has seemed out of reach on the Web. The same simplicity that enabled the Web’s rapid proliferation also creates a gap between the experiences we can provide and the experiences users can get from a desktop application.

That gap is closing. Take a look at Google Suggest. Watch the way the suggested terms update as you type, almost instantly. Now look at Google Maps. Zoom in. Use your cursor to grab the map and scroll around a bit. Again, everything happens almost instantly, with no waiting for pages to reload.

Google Suggest and Google Maps are two examples of a new approach to web applications that we at Adaptive Path have been calling Ajax. The name is shorthand for Asynchronous JavaScript + XML, and it represents a fundamental shift in what’s possible on the Web.

Ajax is a combo of several standard technologies that work together in new ways. It combines the presentation of XHTML and CSS with data interchange and manipulation with XML and XLSLT, along with asynchronous data retrieval with XMLHttpRequest. It uses the Document Object Model for dynamic display and interaction, and JavaScript to bind everything together.

Enthusiasm is building for Ajax. Dan Grossman writes in his blog, A Venture Forth:

Ajax programming techniques have recently generated lots of buzz for good reason: they can be used to create interesting browser-based applications that do things many thought impossible with typical web browsers…”

Grossman describes three problems that Ajax developers need to overcome:

First, Ajax introduces potential user interface issues. In particular, poorly designed Ajax applications work in ways that aren’t intuitive for the average user… Second, Ajax requires JavaScript and, for Microsoft’s Internet Explorer, ActiveX must be enabled… Third, Ajax developers need to be especially mindful of perceived application performance.

You can, however, get around the ActiveX requirement in IE by using this workaround, or use alternatives to Microsoft’s browser and platform.

Ajax development is an area to watch if you are interested in weaning your computer of software that depends on any particular operating system. I’ll be testing Writely over the next month or so and report back what I find.