Firefox 3.5 has become the most popular browser, finally wresting the lead away from industry behemoth Internet Explorer 7, according to analytics site StatCounter. The latest trends show that a huge decline is being seen in IE7 use – as people have started moving over to the latest IE8 – combined with a big rise in Firefox 3.5 that has finally caused a change at the top of the browser leader board.

And the trend lines favor Firefox in the long run: IE’s market share continues its slow decline while Firefox has sustained steady growth over the recent years. StatCounter uses its tracking codes on 3 million websites (5 billion total pageviews) to generate the numbers and this recent revelation is based on this powerful pool of browsing data.

However, as you can clearly see the above graph doesn’t include Google Chrome while comparing the stats, although the ‘other’ category has experienced a significant rise. It would have been certainly interesting to see how Chrome has been performing as compared to other industry leading top browsers.

At any rate, IE8 is rising fast (along with Windows 7), but over the last few months the slope of Firefox’s worldwide curve has been steeper. (In the US, IE8 has always been ahead of Firefox 3.5; in Europe Firefox has led since late summer.) But what is most unfortunate is the fact that IE6, though down, still has a 14% global share (5%-7% in the US and EU; China and Korea are holding up IE6’s numbers). I seriously wonder when the world will cease to use IE6.

However, lest the anti-Microsoft brigade get too excited, it should be pointed out that the combined weight of IE6, IE7 and IE8 far outweighs Mozilla’s Firefox, which pushed users much more heavily to the latest version.