Data from Net Applications -- which lumps mobile and desktop operating systems into one statistic -- show that Windows market share dropped from 93.74 percent in February 2009 to 90.29 percent in December 2010. Windows was still above 92 percent market share as recently as February 2010 but suffered steady losses during the rest of the year.
"The operating system usage market share trend line points to Windows' overall usage falling below 90 percent sometime during 2011," says Vince Vizzaccaro, executive vice president of marketing and strategic alliances for Net Applications. "The timing depends on several market forces. It could be as early as next month, or possibly not at all."
Microsoft's continued dominance of the desktop operating system market will likely not be enough to keep Windows' total share above 90 percent, because the proliferation of smartphones and tablets is changing the definition of what a personal computer is. Microsoft's mobile efforts revolving around Windows Phone 7 in smartphones and Windows 7 in tablets will be crucial for Redmond.
IT analyst Jack Gold, writing in TheStreet.com, predicts "By 2013, greater than 67 percent of browsers accessing the Internet will be on non-PC devices. Internet Explorer will ultimately become a minor player in the browser market, with WebKit-based rendering engines powering the majority of mobile devices, and Mozilla-based browsers being deployed on Linux-based (and Meego-based) larger products. As a result, websites will no longer be optimized for PC-based Internet Explorer, but will standardize on WebKit and HTML5 for broad-based browser compatibility."
For now, though, most personal computing is still performed through Windows. StatCounter, another market share tracker similar to Net Applications, reports desktop and mobile operating system share separately, instead of combining them into one statistic. The combined desktop share of Windows XP, Vista, and 7 is still at 91.94 percent, compared to 6.25 percent for Mac OS X and 0.75 percent for Linux, StatCounter's figures show.