The Mozilla Foundation, the creators of the open-source Firefox browser, has predicted that by the end of 2005, it will have 10% of the browser market. It doesn't take rocket science to realize that's a swing at Microsoft (NASDAQ:MSFT), given the near ubiquity of its Windows operating system and its Internet Explorer browser.

Sure, there are other browser choices out there, such as Opera, Time Warner's (NYSE:TWX) Netscape, and Apple's (NASDAQ:AAPL) Safari. However, none of these have received quite the publicity that Mozilla has over the course of nearly a year of Microsoft's high-profile insecurities.

ZD Net UK reported that, tracking visitors to its own sites, there's been a noticeable increase in Mozilla users. Last February, 9% of its visitors used Mozilla to access the site, increasing to 19% in October. Meanwhile, Microsoft's Internet Explorer use dropped from 88% to 79% over the same period.

For a little bit more anecdotal evidence, anyone who plays around with Google's (NASDAQ:GOOG) Blogger and surveys its traffic using a site meter has probably noticed some increase in visitors who utilize Mozilla (as well as the Linux operating system). Even seeing a small slice of site traffic that happens by a blog could be an eye-opening experience in terms of the types of browsers and operating systems that are being used by surfers around the globe.

For now, claimed that Firefox reached the 5 millionth download marker on Oct. 16, with its latest download count at a little more than 6 million. ( appears to be the open-source answer to a guerrilla marketing campaign.)

The close ties between Microsoft's Windows operating system and its Explorer browser have caused security issues that continue even now, creating opportunities for rivals. However, despite the interesting rumors, news reports have it that Google is still publicly insisting that there is no "Gbrowser" bubbling away in its labs. (On the one hand, a Gbrowser might put a damper on any other contenders, but imagine what Google and Mozilla might do if they teamed up.)

Although increasing defection from Internet Explorer isn't a reason for Microsoft shareholders to panic, it does represent a slow slippage in users' trust. Meanwhile, as the hacker community's favorite foe, Microsoft has got its work cut out for it as far as making users feel secure again -- and eventually, that could be a threat to the top line.

Do you think that more and more people will switch to a browser other than Internet Explorer? Or is this all much ado about nothing? Let other Fools know how you feel on the Microsoft discussion board.

Alyce Lomax does not own shares of any of the companies mentioned.