Apple Inc.'s OS market share has increased by nearly 32% in the last year, according to data collected by an Internet metrics company.

Last month, Apple's Mac OS X accounted for 7.94% of the operating systems powering computers that accessed the 40,000 Web sites Net Applications Inc. monitors for its clients, the company reported yesterday. A year ago, Mac OS X's usage share stood at 6.03%.

Also showing gains in June were Microsoft Corp.'s Windows Vista and Linux, which climbed 8% and 18%, respectively, to end the month accounting for 16.14% and 0.88% of the online OS market.

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% to 71.2%, a decline of nearly a full percentage point. Windows 2000, meanwhile, continued its long slide, dropping to 2.11% of the online operating system share during June.

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

While Windows Vista's 256% 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.