Firefox 4 is stomping on Internet Explorer 9, having tallied over five million downloads in its first 24 hours of release.
The figure's double that clocked up by IE9 in its own first day out just a couple of weeks ago. Even so, though, it still falls short of the eight million downloads for the previous version of Firefox clocked up in the comparable period.
Now showing over six million downloads, the company's counter shows most activity is in Europe, with North America trailing by quite some margin.
Mozilla currently claims an installed base of over 400 million users. However, it faces stiff competition from Google's Chrome - which also has a new, shinier version just out, and now accounts for more than ten percent of the worldwide browser market. Chrome's become something of a pacemaker for the industry, with many of the same features that are now included in Firefox 4.
Firefox 4 took quite some time to come to market, initially being slated for a November release, but this could change in future: the company says it plans to make new versions available every couple of months from now on, in the same way as Google does with Chrome.
It's available to download for Windows, Mac OS X and Linux in more than 80 languages, and will appear on Android and Maemo devices soon. IE9 only runs on Windows 7 and Vista, whereas Firefox and Chrome also work on Windows XP.