Codenamed Apollo, the software developers kit (SDK) and runtime application are designed to help build software that works across operating systems. The software relies on HTML, JavaScript, Flash, and Adobe Flex. The alpha version, which presently works on Windows and Macintosh, can be downloaded for free at www.adobe.com/go/apollo.

Once the Apollo apps are created, users can launch them from their desktops, without using their browser or connecting online. An Apollo application can connect automatically to online data or services when an Internet connection is detected, with new components automatically downloaded and integrated. The user needs the Apollo runtime to run the apps, just as a Flash player is needed to run Flash animations.

Auction Giant Tests Apollo

Adobe said Apollo will make the development and use of rich Internet applications (RIAs) -- Web applications that have the interactivity of desktop apps -- quicker and easier. RIAs can offer more interactivity than is usually available via the Web.

The San Jose, California company said upcoming versions of Apollo will run on Linux , integrate PDF, provide deeper Ajax support, extend support for mobile technologies, and enable media assets to be dragged and dropped directly into Apollo apps.

Auction giant eBay is using Apollo to develop "a fun, immersive experience outside of the browser," according to a statement by Max Mancini, eBay's senior director of disruptive innovation. With Apollo, an offline version of the eBay marketplace "is brought straight to users' desktops," he said, "with improved caching, real-time product availability notifications, and auction updates."

'Great Potential'

Apollo has great potential, according to Laura DiDio, an analyst with Yankee Group.

"It's designed to link online functionalities with advanced client and desktop features," she said. "Adobe is betting on the idea that there is a lot demand for dedicated, desktop application interfaces to online services, that can be 'written once, run anywhere.'"

For business users, DiDio foresaw the possibility of new kinds of fully featured, collaboration software that permits users to keep working when offline but automatically become part of a group when online.

"Adobe says that Apollo will be easier to use, easier to install, more leading edge, and a more reliable and consistent platform" for creating RIAs than existing solutions, she said. She expected the Apollo runtime -- essentially, a player -- to be available for free in its final release.

Apollo developers can use the development environment of their choice, including Adobe's own tools, such as Flash, Dreamweaver, and Flex Builder. Developers will be able to build Apollo desktop applications in less time than it would take to build traditional apps, the company said. Non-Adobe alternatives to developing RIAs include Microsoft 's Windows Presentation Foundation (formerly Avalon) and the open source OpenLaszlo.

A beta version of Apollo is expected this summer, with the first official release later this year. Prices were not announced.