Microsoft is recruiting beta testers for the next version of its Windows XP Media Center Edition product, which is expected to be out by the third quarter of 2004.

Media Center Edition is the Windows XP derivative that powers home-entertainment hubs made by Gateway, Toshiba and other Microsoft OEM partners.

If Microsoft sticks to its current Windows Media Center launch pattern, the new version, code-named "Symphony," will launch this fall. If Microsoft follows current naming conventions, the new release will likely be christened Windows XP Media Center Edition 2005.

The Windows Media Center Extender technology that Microsoft launched at the Consumer Electronics Show in Las Vegas will require the "Symphony" version of Windows Media Center in order to operate. Microsoft has said it plans to ship three flavors of its extender software – for set-top boxes, TVs and Xboxes – by this holiday season. Media Center Extender is designed to allow customers to run Media Center content on a variety of home-entertainment devices.

Microsoft sent out the beta invites for Symphony around January 19, as noted on a variety of Windows enthusiast sites, including Neowin and BetaNews.

"Dear Prospective Microsoft Beta Tester," commenced the invite. "You have been nominated as a prospective candidate for an upcoming beta program. The program will introduce you to a set of technologies providing new digital media experiences on Windows consumer PCs."

Potential beta testers need to respond February 7 to be considered for inclusion in the test program.

Microsoft has more than one version of Media Center in the works. In addition to Symphony, the 2006 version, code-named "Slalom," also is under development.

Windows Media Center, like the Windows XP Tablet PC Edition, is a superset of the Windows XP operating system. Changes that Microsoft makes to the core Windows product are reflected in each version of Windows Media Center. And a number of the advances that the Windows Media Center team builds into its platform are, in turn, adopted by the core Windows team when building their next version of Windows.

(This article is excerpted from the January 20, 2004, edition of the Microsoft Watch newsletter.)