French web survey company XiTi Monitor has published Firefox market share statistics for 2007, which indicate that the open-source web browser is continuing to see gains at the expense of Internet Explorer, particularly in Europe.

XiTi's breakdown of monthly Firefox market share gains for the past year show that the browser climbed from about 20 percent two years ago to 23.1 percent in December 2006 to a record 28 percent in December 2007. Firefox market share hit a plateau and hovered around 27.7 percent between June and September before taking a 0.7 percent drop in October, but then recovered prior to reaching 28 percent last month.

XiTi also provides market share statistics for 32 individual European countries. Finland currently has the highest Firefox market share in Europe with 45.4 percent, followed by Slovenia with 44.6 percent and Poland with 42.4 percent.

In December alone, Internet Explorer fell to 66.1 percent in Europe after losing 0.9 percent market share. During the same time period, Firefox gained 0.7 percent. The statistics show that Safari currently has only 2 percent market share in Europe.



Data source: XiTi Monitor

XiTi also provides some insight into adoption rates of recent versions. Less than half of all Internet Explorer users are running Internet Explorer 7 rather than earlier versions, whereas 93 percent of Firefox users are running Firefox 2.



Firefox market share by country (percent); Data source: XiTi Monitor

Firefox's continued success in Europe may undermine some of the arguments made by Norwegian browser maker Opera in an antitrust complaint filed against Microsoft in December of last year. Opera accused Microsoft of abusing its dominant position in the web browser market by tying Internet Explorer to Windows. Earlier this month, the EU decided to open an investigation against Microsoft in response.

Firefox adoption is likely encouraged by the perception of superior security and the availability of extensions and other user-driven enhancements. Firefox's current market share growth rate was decent in Europe in 2007, but the official release of Firefox 3 (which is currently in beta stage) could potentially incite more significant market share increases in 2008.