Microsoft plans to include in the next version of Windows features to manage Web content distributed via RSS, an increasingly popular way of reading online news and blogs.

Windows Longhorn will include features to help PC users subscribe to information published by bloggers and Web news sites using the Really Simple Syndication protocol. Longhorn will also include a special database and API to make RSS feeds available to desktop apps, Microsoft said.

A test version of Longhorn--the desktop operating system due late next year--that Microsoft plans to distribute at its Professional Developers Conference in September will include the ability to subscribe to news feeds, blog entries, and other Web content published via RSS from within the Windows user interface. The feature will require the upcoming version 7 of Microsoft's Internet Explorer Web browser, due in test form this summer. Longhorn will also be able to store data from RSS feeds in a central place on a PC's hard drive and make it available to apps such as PC calendars. "We're making a really big RSS investment in Longhorn," says Gary Schare, Windows product-management director. "We think RSS will work better than past push technology."

The RSS protocol, based on XML, is a popular way for authors of online news sites, blogs, and audio "podcasts" to automatically alert their subscribers that new content is available. Today, most PC users who subscribe to RSS feeds view entries with special reader software or through Web sites like Technorati.com and Bloglines.com that aggregate the feeds. Apple Computer has built some support for subscribing to RSS feeds into its Safari Web browser, and the Mozilla Foundation includes the ability to bookmark RSS headlines in its Firefox browser.

But RSS still hasn't caught on with most PC users, says Matt Rosoff, a Directions on Microsoft analyst. "It's cutting-edge technology but not something that would enlist a ton of new users," he says. RSS could become more popular if Microsoft builds into its Office apps features that consume information published that way, Rosoff adds.

For its part, Microsoft says it hopes to expand applications for RSS-syndicated content. "We want to enable RSS at the Windows platform level to open it up to new developers," Schare says. On Friday, Microsoft published extensions to the RSS protocol for viewing and sorting lists of entries--such as items on an E-commerce site or songs from an online music store--by their popularity or other criteria. Currently, RSS entries appear in reader software by the date they were published. Microsoft published the extensions under the Creative Commons license, a public domain licensing organization founded by Stanford University law professor Lawrence Lessig.

Some of the features Microsoft plans for Longhorn will be available to Windows XP users as well. The RSS extensions and ability to subscribe to feeds from within Windows will also appear in a version of Internet Explorer 7 for Windows XP, Schare says. But users will have to wait for Longhorn to take advantage of the "common feed store" for desktop software that Microsoft is developing. That technology is scheduled to debut in a test version of Longhorn due in mid-September at Microsoft's developers conference in Los Angeles. Schare says it won't appear in the "beta 1" version of Longhorn, which is expected in August.