Solution providers applauded the launch of Firefox 1.0 as the first viable competitor to Microsoft Internet Explorer, even though they expect the browser's publisher to face an uphill battle.

The much-anticipated Firefox 1.0 browser, released Tuesday by the Mozilla Foundation, had been under development for two years. The open-source browser features an advanced user interface, pop-up blocking, tabbed browsing, faster search, customization and extensibility.

Firefox 1.0 is the first major new product release from the Mozilla Foundation since the Mozilla Suite 1.0 in June 2002. Solution providers said they do not expect Firefox 1.0 to usurp Microsoft's IE, which now commands more than 90 percent market share as the embedded browser in the Windows operating system. Nevertheless, the security vulnerabilities, worms and virus attacks that plague Internet Explorer have opened the door to competition, and Microsoft could see some defections, partners said.

"It's a huge issue for Microsoft," said one partner, who asked not to be named. "The browser security flaws have users fed up."

Firefox offers a migration facility that brings over bookmarks and other tools to ease switching from IE. It will also be made commercially accessible as the default browser on new Linux desktops, including Novell's Linux Desktop 9 launched Monday and Red Hat's forthcoming Enterprise Linux 4 product line, due the first quarter of 2005.

Ironically, Firefox is partly based on Netscape Navigator -- the first Internet browser whose highly publicized fall to Internet Explorer led to the government's antitrust case against Microsoft in the mid-1990s.

Some see a new battle brewing on the browser front between proprietary software companies and open-source organizations. Sources said AOL is now developing a new browser that will be based on Microsoft Internet Explorer.

Open-source backers describe Firefox as the killer application that will drive more adoption of the Linux desktop, saying it's a better open-source alternative to IE than earlier attempts by Mozilla and others.

"It's much more than a browser share war. It's a war for open standards, and the forces opposing Microsoft are much heavier than a company," said Sam Hiser, a consultant and developer for OpenOffice, an open-source competitor to Microsoft Office. "For Microsoft, it is about preserving their nefarious capability of dictating Web page design habits, which are dependent on Microsoft's browser. Firefox represents a challenge to such a racket."

Microsoft charged back hard this week, claiming that Internet Explorer has become the default Web browser because of its ease-of-use and advanced feature set. Microsoft also maintains that many of IE's security problems have been fixed in Windows XP Service Pack 2. Released in August, XP SP2 includes security protection as well as features for handling spyware, malware and download monitoring.

The Redmond, Wash., software giant also claims that the long list of third-party applications available for IE demonstrates the browser's maturity and widespread acceptance as the platform for Web application development. The company warned customers to expect application incompatibilities if they switch from IE to Mozilla. Such incompatibilities could cause problems for business customers, who won't have a vendor they can hold accountable.

"If they consider changing browsers, they need to understand how to centrally control security settings and what support is available if something goes wrong," said Gary Schare, director of product management for Windows. "If you're building a line-of-business app, who do you call and how do you get support? Microsoft has honed its support system, and we can get customers back up and running and get them hot fixes."

Linux solution providers said Firefox's cross-platform support and flexibility offer key advantages for customers of all sizes. They also point out that open-source projects sponsored by Mozilla and others will give ActiveX developers greater choice as well as address compatibility and bug issues.

"The advantage for Firefox is that it provides the tools to customize a browser with appropriate settings and capabilities to meet requirements. It can then be deployed across Windows, Linux, Solaris and HPUX," said Anthony Awtrey, vice president of Ideal Technology, Orlando, Fla. "When a business develops Intranet applications to work with Firefox, they will know it will work across the enterprise."

Firefox will integrate Google Search, Yahoo, eBay and Amazon, according to Mozilla. More than 100 extensions are currently available.

While many view Firefox as the first viable competitor to Internet Explorer, loyal Microsoft partners said most clients will consider it a hassle to either switch or support two browsers.

"Browser choices are only something that is an issue among the super geeks, and not the average user, especially in SMB," said Michael Cocanower, president of ItSynergy, Phoenix. "If they can get to MSN, conduct business on the Web, download and open PDF files, then they are happy. There is no reason to go to the expense and time of installing alternate browsers when these users just need the basics."

Jeffrey Sherman, president of Warever Computing in Los Angeles, said a handful of customers have expressed interest in Firefox, but he is skeptical of its chances.

"There are some sites that simply must be accessed with Internet Explorer. Does it make sense to use one browser most of the time and another for specific sites?" Sherman asked. "Not one of my clients has shown an interest in alternative browsers, except for a few individual users here and there who are die-hard Netscape users."

One industry observer said Mozilla's timing couldn't be better. "Right now there is a very strong opportunity for a third party. The perceptions surrounding Microsoft's offerings are not positive and, until that is corrected, Microsoft remains exposed," said Rob Enderle, principal of The Enderle Group.

But, Enderle added that Mozilla faces a remarkably well-entrenched competitor. "There's a huge amount of infrastructure now that depends on IE. Working for Microsoft is the massive amount of third-party work that is tested on this platform and the improvements made with SP2, which made the platform more resilient to attack."

One Linux solution provider agreed that it will be an uphill battle for the Mozilla Foundation, but said timing is on Mozilla's side. "Most companies are just using whatever comes with their operating system, unless there is a compelling reason to switch," said Chris Maresca, senior partner at the Olliance Group, Palo Alto, Calif. "A number of them have been looking at Firefox for security reasons."