According to Net Applications, in June Windows Vista accounted for 4.52 percent of all systems that browsed the web, up from January's 0.18 percent. Vista has grown its usage share each month since its release to consumers January 30, hitting 0.93 percent in February, 2.04 percent in March, 3.02 percent in April and 3.74 percent in May.
Apple's Mac OS X, meanwhile, accounted for 6.22 percent in January and hit its high point of 6.46 percent in May, but it slipped back to six percent in June.
If Vista's uptake trend continues, it should pass Mac OS X in web usage share by the end of August.
Vista's increases have come at the expense of Windows XP and Windows 2000, both of which have dropped in usage since January. Windows XP, for instance, accounted for 85.02 percent of all machines that month but was down to 81.94 percent in June. Windows overall total has remained flat, ranging between 90.01 percent and 90.46 percent through the first six months of the year.