Mozilla has begun notifying Firefox 3.6 users that now is a good time to upgrade to Firefox 8.0.1--and to the browser\'s new fast-moving ethos.The change had been planned for at least two other occasions in recent weeks, but Mozilla postponed it. But yesterday, Mozilla flipped the switch so that when Firefox 3.6 checks with a server to find out if there\'s an update, it\'ll find the newest version of the browser.\"It\'s live, and users should see an update in the next 24 hours,\" said spokeswoman Erica Jostedt. Mozilla has a Web page for users to check if they have the latest Firefox version.Mozilla released Firefox 3.6 in January 2010. After Firefox 4 a year later, Mozilla moved to a rapid-release philosophy in which new versions of the browser come every six weeks with smaller changes.Firefox 8 is the most widely used version of Mozilla\'s browser, accounting for 7.3 percent of personal-computer browser usage in November, according to statistics from Net Applications. Firefox 3.6 is next, with 5.3 percent, so a lot more people likely will get on the rapid-release train now.Firefox is in a competitive race, primarily right now with Chrome. Google\'s browser is in third place but closing the gap with Firefox.The rapid-release plan, modeled on the same practice Google adopted with Chrome, lets Firefox deliver new features without browser users having to wait a year or more for a new major version. It\'s irked some people, particularly business customers, who don\'t want a fast-moving product, so Mozilla is working on a slower-release plan, too.The rapid-release update process also produces a lot of intrusive notifications for Windows users. Mozilla is working to ease that annoyance with silent updates.