
The web browser, run by the not-for-profit Mozilla Foundation, is likely to reach the landmark today or tomorrow and has asked its community to send in photos to form part of a .
The campaign is likely to raise Firefox's profile further, at a time when the browser is very much on the up, while Microsoft's Internet Explorer is very much on a downward curve.
While the global market share of Firefox has grown every quarter bar two since 2004, the market share of Internet Explorer has fallen every quarter bar one.
Firefox now has 22.39 per cent of the global browser market compared to 65.85 per cent for Internet Explorer, 8.46 per cent for Safari and 1.74 per cent for Google Chrome, according to Net Applications.
Internet Explorer has dropped nearly eight percentage points in market share since Q2 2008, according to the statistics, while Firefox, Chrome and Safari have all recorded strong growth.
Mozilla said that it expects the billionth download to take place today, after which it will launch the celebratory campaign.