(CNET) -- Five years ago, Mozilla made it clear that the browser wars weren't over after all.

In the 1990s, Netscape had lost its dominance in the browser market to Microsoft's Internet Explorer, and the Netscape-spawned open-source project called Mozilla had sunk into obscurity. Even a federal antitrust suit accusing Microsoft of anticompetitive practices with its browser and Windows was not enough to turn the tide. But on November 9, 2004, Firefox 1.0 emerged to fight back again.

The project, originally named Phoenix to symbolize rebirth from Netscape's ashes, has now clawed its way back to account for nearly a quarter of the browser usage today. Microsoft may not be on the run, but it's on the defensive, gradually building its browser development effort back up into fighting form.

Firefox eyewitness

It's a history that Mike Shaver, currently Mozilla's vice president of engineering, saw firsthand since joining Netscape in 1997.

Then, he was a young programmer whose work with Linux gave him open-source inclinations. He'd been advocating an open-source release of the engine within Netscape Communicator that ran Web-based JavaScript programs, but was surprised in 1998 when Netscape announced the entire software package would become open-source software.

"For me it was confluence of being at the right place at the right time and having a lot of contacts," Shaver recounted. He jumped into thorny issues of making a large commercial project into an open, cooperatively developed project: licensing, trademarks, patch reviews, schedules, governance.

The open-source move was intended to counter Microsoft's growing browser clout. Initially, it failed, but the open-source move ultimately planted the seeds for Firefox's success. That's because the open-source ethos--which lets anyone see, modify, and distribute a program's underlying source code--is what enabled programmers to build something lean and mean out of what some saw as the bloated and uncompetitive Mozilla product.

Microsoft helped out in its own way by letting Internet Explorer languish and become a preferred channel for computer attacks, but Firefox features such as speed, a tabbed interface, the ability to accept add-on customizations, and pop-up ad blocking helped, too. Firefox 1.0 arrived was downloaded 10 million times in the first month.

"When we got to Firefox, in some ways it was overnight success. Our initial growth was more than we'd ever hoped for," Shaver said. "From where we started this undertaking--the strategic context within Netscape--to being the single biggest force behind the rebirth of the browser as an interesting software category...It's a pretty amazing end point."

Overall, the browser market has become more vigorous than ever. Even Microsoft is getting involved in Web standards and is building a Web-based version of Microsoft Office. And even as Firefox's leaders must grapple with the old rival, there's a new Firefox challenger in the form of Google Chrome.

Phoenix from the ashes

In Shaver's view, Mozilla has gone through two trials by fire. First was the transformation of the Netscape effort and the initial release of the Mozilla software as an open-source project.

"The first big test for us was around release of Netscape 6. Between that and Mozilla 1.0, we were open-source's greatest failure," Shaver said.

Second was the decision in 2003 to abandon that effort and throw the Mozilla weight behind what became Firefox.

"Getting the community aligned around that product change was our second big test around the health of the project," he said. "It was a touch-and-go period."

And though there was plenty of positive feedback from the outside world about Firefox, it took a long time before everybody was on board. "It was not until Firefox 2," which arrived in October 2006. "It took quite awhile for the core developers to prefer to work on Firefox than the suite."

But there were meaty challenges for programmers, and Microsoft's complacency left abundant opportunities. "You could look at the dominant browser at the time, pick any dimension and exceed them," Shaver said.

Firefox also gradually won the support of Web developers. Supporting another browser besides IE meant work, but Firefox's eventual widespread use made it worth the trouble. And Mozilla's effort to support Web standards lowered the difficulties for others to introduce browsers, too.

Google's helping hand

The seeds for Mozilla's financial success--measured on the basis of an open-source project if not, say, Microsoft--were sown early in Firefox. The software's start page was a rebranded window to Google's search engine, and a separate search box in the upper right drives more queries to the site.

Mozilla gets a cut of the resulting search-advertising revenue; in 2007, the last year for which Mozilla has released figures, Google supplied 89 percent of Mozilla's $75 million in revenue.

Google co-founders Larry Page and Sergey Brin took a personal hand in boosting Mozilla, Shaver said.

"Google's founders Sergey and Larry were very supportive. They wanted to find a way to help," Shaver said. "They wanted to see what we could do about the traffic we were sending there...They had a lot of stuff to take care of, but for a long time they were Google's reps to us."

And Google contributed code, too--spell-checking, network stack software.

Among Google programmers who helped were Ben Goodger, a Firefox programmer, and Aaron Boodman, who came up with the Greasemonkey software for customizing Firefox's interface.

"It was certainly helpful," Shaver said. "It was always very independent from the revenue relationship," and Google to its credit didn't use its search-engine deal to exert pressure on the browser's development direction, he said.