More and more applications that used to be tied to the desktop are now available on the Web; well-known examples include Google Docs, the search giant's online word-processing program. (See "Google's Cloud Looms Large.") But as people become used to running applications and storing their data online, Adobe is working on technology that will bring those applications back to the desktop again, transformed by their time in the "cloud." Called Adobe Integrated Runtime (AIR), the technology is intended to help developers take advantage of the strengths of both Web-based applications and traditional desktop applications.

Adrian Ludwig, group product market manager for the technology, explains that AIR applications can run whether the user is connected to the Internet or not. Like desktop applications, AIR applications will be able to store information locally on the user's computer. Users can also access data from the desktop: they can easily drag and drop information into and out of an AIR application. When the user is online, the applications can function as Web-based programs do, giving instant access to up-to-date information, regardless of what computer is used to retrieve it. When the user is offline, the AIR applications continue to run, waiting to synchronize data until the user connects again.

"We're blending together the desktop and the Web application," Ludwig says.

Users don't have to be particularly aware of AIR, he says. Like Adobe's ubiquitous Flash player, AIR is a plug-in that users download the first time they want to use an AIR application. All subsequent AIR applications can be downloaded without any additional fuss. And like Web pages, AIR applications are designed to work regardless of what type of computer a user has; the programs will work on computers running either Windows or Mac OS. (Adobe is also working on a version of AIR for Linux.)

For programmers, however, developing for AIR is very different from creating applications that run on a user's desktop. Instead of being written in computer languages such as C++ for a specific operating system, AIR applications are written using the tools of Web development, such as HTML, JavaScript, and Flash.

Several companies have already built applications using AIR, including eBay, Nasdaq, and fashion retailer Anthropologie. These early applications illustrate a variety of approaches to using AIR. The eBay application, for example, is designed for power users who want access to the auction site at all times, Ludwig says. Not designed with offline features, the application uses its integration with the desktop to feed alerts to the user, such as a bouncing icon in the dock on a Macintosh when someone bids in an auction that a user is following.