Firefox hit 400 million mark for its downloads as reported over spreadfirefox. Also my favorite browser, it supported add-ons / extensions, tabbed browsing and the themes which made it go top of the charts just when it was launched in Nov 2004. These features are being copied in almost every other browser today including IE 7 and tehrefore, Firefox gets the credit for bringing the revolution in browser arena, long back.
Still, it is much ahead of other browsers specially when it is getting updated at much faster pace than others and next version is scheduled later this year. A must try browser.
I don’t know but these day, I am getting only problem with my Gmail in Firefox over Vista which appears from the add-ons installed – so be careful while installing more of extensions.