There have been a billion downloads of Firefox.
The BBC reports
The open-source browser Firefox passed its billionth download on Friday, ahead of the release of its fourth iteration.
The milestone includes downloads of all versions of the web software since its first release in 2004.
Figures suggest that Firefox now has nearly one third of the browser market worldwide, at 31%.
Though I use other browsers, generally Firefox is the browser I probably use the most. Some of those billion are my downloads.