Microsoft previewed new features of its forthcoming version of Windows at PDC (Professional Developer Conference) in Los Angeles today, including the return of the Sidebar.

The Sidebar is an area of the desktop in which small custom applications, called gadgets, can run. The functionality of gadgets is similar to that of widgets seen in Apple's latest operating system, OS X Tiger. Originally featuring in early builds of Vista, Sidebar disappeared in the last beta release.

In a technical demonstration, Chris Capossela, Vice President of the Information Worker Group for Microsoft, explained how gadgets can display up-to-date information to the user.

"The Sidebar [shows] real-time information that I deal with all the time," he said, before running through some examples including a web feed gadget, a clock gadget, a search gadget, a picture library gadget and a picture slideshow gadget.

In addition Microsoft expects developers to create their own gadgets to further enhance Vista, Capossela explained.

Capossela also gave a demonstration of a related feature called Sideshow that provides a basic interface for gadgets through custom hardware. "Sideshow is another platform that you can build fantastic gadgets for. We're working very closely with our hardware partners to support the Sideshow," he said.

Showing off a device using Sideshow, he explained, "this is just a laptop that's got an auxiliary display, with a couple of hardware buttons here that I can click on. And it's running some mini applications or gadgets for the Sideshow."

"Some of these gadgets run when the PC is turned off, such as the Inbox or Calendar, and some of them require the PC to still be powered on, such as controlling your music," he said.

More information on gadgets is available at