Software maker Adobe Systems launched new software to make it easier for programmers to build applications that work online and offline.

Adobe Air allows developers to build tools that still have some functionality even when a computer is no longer connected to the net. A free download will allow users of Macs, PCs and, later this year, Linux machines to run any Air applications.

Websites such as auctioneer eBay have already developed applications that use the new technology. After a quick download, the eBay users can click the company's logo on their desktop and launch an application that will allow them to do their business directly - no browser required.

The software is part of a growing number of technologies that aim to make the transition between the on and offline worlds seamless.

In 2006, Microsoft unveiled its Silverlight technology. And last year Google launched Gears.