On November 9, 2004, Mozilla released the first version of Firefox.
The free browser became an instant success and was downloaded 100 million times in its first year. Firefox became the first challenger of Microsoft's Internet Explorer which held a market share of 90% back then after having defeated Netscape Navigator in the first browser war. Firefox's emergence rang in the second browser war, which saw the Internet Explorer's market share gradually erode as more and more browsers entered the market.
After having been the number 2 behind IE for years, Firefox was surpassed by Google's Chrome browser earlier this year. Chrome, which made its debut in 2008, quickly opened up a lead and currently holds 21.3% market share compared to Firefox' 13.9%. Microsoft's Internet Explorer remains the clear frontrunner with a market share of almost 60%.
This chart shows the worldwide desktop market share of the world's second and third most popular web browsers: Google Chrome and Mozilla Firefox.
You will find more statistics at Statista