Firefox, a browser based on the Mozilla Foundation's open-source development work, is scheduled to be available for free download at 1 a.m. PDT Tuesday.
If the download statistics from preview releases of Firefox are any indication, the open-source browser could be headed for a big debut.
"Our browser is moving into the mainstream," said Mitchell Baker, president of the nonprofit Mozilla Foundation, based in Mountain View, California. "Being an alternative browser in today's market is a challenge, but people have begun to realise that the browser matters, that the browser you get with your computer can be a beginning point and not an endpoint."
The browser Mozilla releases in the wee hours of Tuesday morning in the US won't be significantly different from the preview releases that have launched in recent months. Mozilla changed its default start page to appeal to new users, but other changes are minor performance improvements and bug fixes.
But the release could nonetheless make a big impact if pre-release trends propel the open-source browser into serious contention with Microsoft's Internet Explorer.
While Web analysts have largely ignored the browser market since declaring IE the winner of the browser war, scattered Web site measurement statistics have suggested gains for Firefox and other minority browsers against the IE juggernaut.
IE continues to command more than 90 percent of the market, with Opera Software's browser, Apple Computer's Safari browser and other Mozilla-based browsers making up the difference. Firefox has set its sights on gaining 10 percent of the market by the end of 2005.
In addition to making apparent market inroads and shattering its own download goals, Firefox has succeeded in blazing an open-source fundraising trail that backers call unprecedented.
To place full-page ads in The New York Times, the Mozilla Foundation raised more than US$250,000 in donations in the first 10 days of a fundraising campaign.
Mozilla owes part of its Firefox success to widespread security concerns about IE. While all the browsers have faced security bugs, IE's security reputation has suffered chronic damage amid a steady torrent of security bugs and spyware schemes targeting IE users.
The Computer Emergency Readiness Team (CERT), the computer threats division of the U.S. Department of Homeland Security, issued an advisory urging Americans to consider ditching IE in favor of its competitors. Independent groups have launched their own campaigns urging Web surfers to consider IE alternatives.
