Although Microsoft still dominates the Web browser space, its Internet Explorer continues to lose market share to open-source rival Mozilla.
Internet Explorer held more than 95 percent of the U.S. browser market for several years, but its share dropped to 94.7 percent in July and had declined further to 92.9 percent on October 29, WebSideStory, a San Diego Web metrics company, says.

Benefiting from high-profile security vulnerabilities in the Microsoft browser and recommendations by experts to switch, the Mozilla Foundation saw its market share rise. The Mozilla Suite, Netscape, and Firefox held 6 percent of the market at the end of October, up from 3.5 percent in June, according to WebSideStory.
Quick Rise

"It is not a fast drop for Internet Explorer, but it might be considered a fast gain for Mozilla," says Geoff Johnston, an analyst with WebSideStory.

Firefox is the Mozilla Foundation's stand-alone browser. The Mozilla Suite includes a browser, e-mail client, Internet Relay Chat client, and Web page editor. Netscape, distributed by America Online, is based on Mozilla technology. The Mozilla open source project was started in early 1998 by Netscape.

The rise of Firefox has been especially remarkable, Johnston says. The browser--a 1.0 version of which is scheduled to be released November 9--held 3 percent market share at the end of October. Firefox was introduced in February this year when Mozilla renamed its Firebird project.

"It was one thing in July to see Microsoft starting to lose market share for the first time in a trend-like fashion. But we did not know whether it would continue. It has," Johnston says.

Taking advantage of the momentum, the Mozilla Foundation is drumming up support for Firefox. The group has collected $250,000 in donations to take out a full-page ad in The New York Times to promote the upcoming 1.0 release of Firefox. The money will also be used for other promotional activities.
Updating IE

Meanwhile, Microsoft delivered some updates to Internet Explorer with Service Pack 2 for Windows XP (news - web sites) and is working on a new version of the browser that will ship as part of Longhorn, the codename for the next version of Windows due in 2006, a company spokesperson says.

Also, the Internet Explorer development team at Microsoft has emerged from obscurity by starting a Web log.

Microsoft sees the market share fluctuation as the "natural ebb and flow of a competitive marketplace," the spokesperson says.

Users who try other browsers ultimately will come back to Internet Explorer, the spokesperson says. "As they check out the alternatives, we think they'll discover that critical factors such as Web site compatibility, application compatibility, and enterprise management and support are just better with Internet Explorer."