Mozilla.org has made public a report that says its Firefox browser has 30 percent market share worldwide. Assuming it’s true, that is a six percent increase since a news story last November.
The Mozilla Metrics report 1Q2010 says the browser has 39.2 percent penetration in Europe (152.7 million users) and 29 percent in the U.S. (100 million users.) Mozilla claims 350 million users worldwide. Adoption is quickest in Russia (20 percent increase in the first quarter) the report said.

Mozilla Metrics Report here.

In November, ZDNet reported the following browser adoption statistics:

“Internet Explorer 6 is the most commonly used web browser, according to web analytics firm Net Applications. At the time of writing, IE 6 had 23 percent of the market, while IE 7 and 8 each held 18 percent. Rival browser Firefox 3.5 had 14 percent, while Firefox 3 had 9 percent. Overall, Internet Explorer had 65 percent market share, while Firefox had 24 percent.”