If Gartner's assessment of AJAX's position on the Hype Cycle is correct, then the days when AJAX is the only game in town are over. Enter the age of what Anne Thomas Manes of the Burton Group calls 'Fit Clients' - a hybrid of Thick Clients (a.k.a. Fat Clients) and Thin Clients (HTML and RIA).

Gartner Group publishes a type of market analysis every year called the Hype Cycle. In general – as the theory goes – certain products go through the hype cycle where they gain a lot of traction until the hype surrounding the technology reaches its peak. It’s at this point, when expectations have far outstretched the capabilities of the platform, that people realize that the technology has limitations and become disillusioned. Subsequently the popularity for the technology plummets.

Fortunately, the most useful technologies recover from this plummet and eventually reach equilibrium where customer expectations are aligned with the technology's capabilities.

Figure 1 illustrates the Gartner Hype Cycle.

Figure 1: The Gartner EmergingTechnology Hype Cycle

In the course of the past 15 years we’ve seen the Hype Cycle realized over and over again. Rapid Application Development (RAD) with tools like PowerBuilder, Borland Delphi, and Visual Basic went through this process in the early 1990s. Java and Dynamic HTML (DHTML) survived the process in the late 1990s. More recently, according to Gartner Group, AJAX has already past the “Peak of Inflated Expectations” and has started tumbling down toward the “Trough of Disillusionment,”

If Gartner's assessment of AJAX's position on the Hype Cycle is correct, than the days when AJAX is the only game in town is over. Enter the Fit Client.

The latest technology to be “triggered” in the Hype Cycle is what some are calling the “Desktop 2.0,” Rich Internet Clients (RIC), or Rich Internet Applications for the Desktop (RIA Desktop). Regardless of what you call it, Adobe AIR is currently its archetype representative. Adobe AIR is gaining ground as AJAX loses traction.

What’s interesting is that Adobe AIR addresses some of the expectations that were not met by AJAX. It provides a consistent user-experience across desktops, allows for off-line and on-line interactions, and can store and process large data sets stored on the desktop. Specifically, Adobe AIR makes it possible to develop what Anne Thomas Manes of the Burton Group calls “Fit Clients.”

Fit Clients

Fit clients, as Manes describes them, are hybrid of Thick Clients (a.k.a. Fat Clients) and Thin Clients (HTML and RIA). Fit clients embrace the local processing and offline capabilities of Thick Clients while providing tooling normally associated with thin-client web applications. Adobe AIR is definitely a Fit Client technology, but it's not the first and won’t be the only player in this space. Other Fit Client technologies include: Java Web Start, Curl, desktop widget engines (e.g. Google Gadgets, Yahoo! Widgets, Apple Desktop), Google Gears, and SlingShot to name a few. All of these platforms are Fit Client platforms. Adobe AIR is neither the first nor the only technology in the Fit Client space, but it does have the most momentum for now.

Fit Client platforms all implement pretty much the same architecture. They leverage a runtime environment that has been ported to two or more desktop operating systems. End-user applications are written to the runtime, not the desktop, and are therefore portable to every platform that supports the runtime environment. If that sounds familiar it’s because we’ve seen it already: Sun has been promoting its own Fit Client technology, Java Web Start, for about seven years. The fact that Java Web Start was there first raises an interesting question: why didn’t Java Web Start gain the same kind of momentum as Adobe AIR is currently enjoying? The difference is partly marketing and partly timing.

Marketing and Timing

No one is going to accuse Sun Microsystems of being good at marketing. They managed to create the most common software platform in history yet their ability to profit off of that platform is highly suspect. Although Sun is sometimes “marketing-challenged,” Adobe is not. Adobe put on a marketing campaign for AIR that would make Steve Jobs proud. This difference in marketing skill certainly accounts for some of the differences in the adoption rate of Adobe AIR vs. Java Web Start. Still, the success of Adobe AIR probably has as much or more to do with timing than anything else.

AJAX arrived in early 2005 with the introduction of Google’s revolutionary web-based mapping service and the coining of the term “AJAX” by Jesse James Garrett. Everyone was so enamored with Google Maps and the rich interaction it afforded that the desire for other web sites with richer interfaces grew and grew. Today, companies and consumers are familiar with what RIA technologies make possible. We are no longer satisfied with the web as a hypertext platform; we want desktop-like GUIs, smooth animated transitions, and a single page interface. Thanks to Google and all of the AJAX implementations that have followed, we have discovered another side of the web. Call it the rich Internet experience.

The Rich Internet Experience

With the appeal of the rich Internet experience AJAX gained enormous traction. Not since the introduction of Java or XML have I seen a technology gain mindshare among developers and corporations so quickly. But our expectations of what AJAX could do grew beyond the capabilities of the technology. We wanted our rich Internet experience to be more like a desktop experience. This is the climate today and it's the climate in which Adobe AIR was introduced. Great marketing by Adobe played a big role, but so did the natural evolution of consumers’ expectations. We had seen the potential of the rich Internet experience and wanted more. In contrast, when Java Web Start was introduced it made hardly a splash. Java Web Start was introduced into a very different climate. The world was still gun-shy about Java as a client technology (I think we still are).

Google’s use of AJAX techniques helped to kick off our desire for a richer web experience, but it is Fit Client technologies like Adobe AIR, Curl, Google Gears, Google Gadgets, Yahoo! Widgets, and Slingshot, etc. that will carry the rich Internet torch for the next two or three years.