A popular site called Net Applications is often referenced when it comes to the market share of browsers. They also keep note of operating systems to see which ones are the most popular, and looking at some of the stats over the last several months shows that Vista is on a steady upward trend while Mac OS X appears to have leveled off.

Using the data that Net Applications provided I was able to create a chart that demonstrates the increasing market share of Windows Vista, as well as the slight drop in Mac OS X usage:

Vista vs. Mac OS X Growth

I used the data which has been available since February to plot the growth rate of the two operating systems, and according to the trend Vista could be surpassing Mac OS X as early as August 2007. Vista’s growth is, of course, at the expense of other Windows operating systems, and Windows XP now sits at 82% market share after a 3% decrease since February. Windows overall has maintained at least 90% of the market share all year though.

Since Vista is eating away at its own market I’m not really sure whether you can consider this finding substantial, but it does show that Vista is indeed being adopted by new users. I imagine the growth rate will pick up even more when Vista SP1 is released, but at the same time Mac OS X Leopard will be peeking out. Who knows…maybe the new Mac operating system will give the Mac stats a big upward climb that really takes a bite out of the Windows market share!

I believe that these stats are only for the United States which might help explain why Vista hasn’t actually surpassed the Mac OS X market share. Heck, Microsoft announced that 20 million Vista licenses had been distributed in its first month of being available, and some sources say that is equal to the number of Mac users. So in reality Vista probably passed the Mac OS X market share sometime in March, but these web analytics seem to give another point of view.

Source: Info World