Google's Chrome browser reached a milestone in January, surpassing 10% market share for the first time. It came close in December, when Chrome reached 9.98% market share, according to data from analytics firm Net Applications.

Microsoft's Internet Explorer retained the lion's share of the market, with all editions of IE combined now claiming 56% of global browser usage. It is followed by Firefox with 22.75%, Chrome with 10.70%, Safari with 6.3% and Opera with 2.28%.

However IE's share of the worldwide market continues to decline. Compared to the prior month, IE usage fell slightly from 57.08% in December 2010. Firefox usage remained essentially flat (declining slightly from 22.81%), while Safari rose about four-tenths of one percentage point from 5.89% and Opera stayed flat, gaining slightly from 2.23%.

Among the IE versions, IE8 showed growth in January, gaining 1.15 percentage points month to month, Net Applications reports.

"With 34.79% of users worldwide, Internet Explorer 8 remains the most popular and fastest growing browser in the market," commented Roger Capriotti, Microsoft's director of Internet Explorer product marketing, in a blog post today. 

IE9, which is the latest beta version of IE, is also gaining global usage share, reaching 0.5% in January. Windows 7 machines are driving usage of IE9, which now accounts for 1.82% usage on Windows 7 worldwide. According to Microsoft, IE9 has been downloaded more than 23 million times.

IE6 usage, meanwhile, continues to decline. It fell to 11.43% in January, down from 13.06% in December. "IE6 has dropped 3.9% over the last three months (an average of 1.3% drop per month) and 9.31% from a year ago. During that same time, IE8 has grown 9.15% since January 2010," Capriotti says.

Capriotti emphasised in his blog that the trend to get people off IE6 and onto a later version of IE is even more accelerated in the commercial segment: In November 2010, IE6 commercial usage share was at an all-time low of 10.3%, and IE8 was at 34.1%. 

To compile its Net Market Share reports, Net Applications collects data from the browsers of visitors to its global network of HitsLink Analytics and SharePost clients, which includes more than 40,000 websites. The data is compiled from approximately 160 million unique visits per month.