Apple Mac OS X's share of the operating system has increased by almost 32 percent in the past year, according to data collected by Net Applications.

In June, Apple's Mac OS X accounted for 7.94 percent of the operating systems powering computers that accessed the 40,000 websites Net Applications monitors for its clients, the company reported yesterday. A year ago, Mac OS X's usage share stood at 6.03 percent. During the same period, 5.39 percent of visitors to PC Advisor used the Mac OS.

Also showing gains in June were Microsoft's Windows Vista and Linux, which climbed 8 percent and 18 percent, respectively, to end the month accounting for 16.14 percent and 0.88 percent of the online OS market (22.6 and 1.62 percent on PC Advisor, respectively).

Those gains came at the expense of Windows XP, and to a lesser extent, Windows 2000. Net Applications' data showed that Windows XP's share dropped from 72.12 percent to 71.2 percent, a decline of nearly a full percentage point. Windows 2000, meanwhile, continued its long slide, dropping to 2.11 percent of the online operating system share during June.

Monday June 30 marked the first major retirement milestone of Windows XP as Microsoft stopped offering licences to most big-name computer makers and halted sales of boxed copies to retailers.

While Windows Vista's 256 percent increase in market share over the last 12 months significantly outpaced Mac OS X's gains, Windows' overall June total was down 2.45 percentage points from the year before, indicating that Vista was replacing XP, not adding to Microsoft's share.

Net Applications' operating system share and trend data is available online.

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