Firefox 3.5 is world’s most popular browser, StatCounter says Mozilla Firefox 3.5 has passed up Microsoft Internet Explorer 7 to become the world’s most popular Web browser, according to analysis firm StatCounter. Depending on your point of view, this could be huge news. Firefox finally edging out IE7 as the most-used browser? Holy cow. But remember, Microsoft is up to Internet Explorer 8, and StatCounter reported nearly as many IE8 users as Firefox 3.5 users. Source: The Microsoft Blog