Rich internet applications (RIAs) have been the height of web fashion for the past year, and have given internet users more powerful applications with better user interfaces than standard HTML-based websites. For some users, they can complement, or even replace, desktop applications.
But RIAs also have drawbacks. First, they often work by downloading code to run inside the browser, which causes a short delay before they start up. Second, people cannot use them when they do not have an internet connection.
The next step is obvious: instead of downloading code, why not save it on the local PC? The basic idea is to make the application available offline. This can also enable a website to break out of the browser and make the leap to the desktop.
There are several ways to do this, but Adobe is hoping to corner a large chunk of the emerging market with its Adobe Integrated Runtime (AIR). This is a rendering engine that handles both HTML via the Webkit engine and Adobe Flash.
Obviously, HTML and Flash are not the best way to build heavyweight desktop applications, but there are compensations. They provide a way to develop useful lightweight applications, and to develop and deploy them very quickly.
Developers can also provide a rich user interface, and the result should be cross-platform: the application will "play" wherever it finds an AIR. That means Windows and Mac today, in beta, with other platforms to follow.
Another potential advantage is that AIR developers only need to be proficient in ECMAscript and other web technologies, rather than being heavyweight programmers with C++ and similar skills. In other words, Adobe is targeting people who already use products such as Flexbuilder, Dreamweaver, and Coldfusion rather than, say, Microsoft.net or even Java programmers.
There is certainly a market among companies that already have successful websites, and eBay has already released a beta of an AIR applet, codenamed San Dimas.
There is probably a market for cross-platform applications that can do much more than a widget, but less than a full-blown desktop application. How big it is remains to be seen.
As Forrester Research has pointed out in a briefing paper, Rich Internet Apps Move Beyond The Browser, developers now have a wide range of options.
These start with the thin-client HTML-based approach, and go through browser-based, player-based and client-based applications, before reaching full fat-client applications. Or, of course, vice versa.
They all have their pros and cons. The main thing is to pick the right tool for the job.