In fact, this week saw downloads of Firefox add-ons cross the 3 billion mark, according to a Thursday on the Mozilla Blog.

Thats almost half of the worlds population and more than the number of people on the Internet today, wrote Mozilla's Erica Jostedt. This amazing milestone was made possible by the hundreds of millions of Firefox users and more than 25,000 Firefox add-ons developers around the globe.

Mozilla also published the infographic below summarizing some of the browser's key add-on milestones.

85 Percent of Firefox Users

Mozilla's Firefox brought add-ons to the Web back in 2004 as a way to let users of the browser customize its features and functionality. In 2009 add-ons came to as well.