The open-source Firefox Web browser continues to flirt with the 10 percent market share milestone, but Microsoft's Internet Explorer (IE) regained lost ground among Internet users last month -- apparently at the expense of Firefox and Apple Computer's Safari, according to NetApplications.com.

The Aliso Viejo, Calif.-based market research group found that 85.31 percent of Internet users fired up Internet Explorer in January, up from 85.05 percent who did so in December 2005. Firefox, which was used by 9.57 percent of Web surfers in December, saw its share dip slightly to 9.5 percent. However, the latest update to Firefox, Version 1.5, was used by 4.02 percent of users in January, up from 2.45 percent in the prior month.

Apple's Safari browser saw its share also dip slightly from 3.07 percent in December to 3 percent in January. Netscape and Opera also saw their share of users drop.

More than nine out of 10 Internet Explorer users are using Version 6.0. By year's end, Microsoft will launch IE7, which promises Firefox-like useability features and better security.

It has released betas of IE7, including a preview of Beta 2 on Monday. But use of IE7, according to NetApplications.com, remains tiny: 0.04 percent of the market, barely more than those using the 9-year-old Internet Explorer 4.0, which first shipped with Windows 98 nearly a decade ago.