The Mozilla Corporation, which oversees the development of Firefox, says that more than one million people helped create the new release.
The first version of Firefox was brought out in November 2004 and since then has been chipping away at the popularity of Microsoft's Internet Explorer browser.
Mike Schroepfer, vice president of engineering at Mozilla, said that there were about 12 big improvements in Firefox 2.0 along with thousands of minor tweaks and bug fixes.
The changes include a phishing finder that notifies users when they go on to a site that tries to con them into handing over login details for a bank or other valuable service, and a spell checker that keeps an eye on every bit of text typed in almost any Firefox browser box be it in a web-based e-mail program or an add-on that lets people post blog updates directly.
