Microsoft’s Windows XP has been the most popular OS in the world for over 10 years, even long after the next two versions of the operating system release. Vista was hardly a replacement to the far more stable XP when it launched, bit Windows 7’s smaller size, ease of use and a simplified install seem to have done the trick. New numbers revealed by StatCounter suggest that Windows 7 surpassed Windows XP as the most popular OS in October, roughly two years after the former’s launch day.

Pingdom wrote up a piece about the news:

“You’ll see a close correlation between the combined decline of Vista and XP and the rise of Windows 7, which is to be expected. We’ve shown before that Windows 7 users upgrade from Windows XP and Vista, not from other operating systems. Windows eats Windows, OS cannibalism, so to speak.”

As Windows 7 gains in popularity, Microsoft’s R&D teams are working on Windows 8, the next mobile-oriented version of the OS. The company implemented some of the early feedback users sent about the developer preview it released a month ago. There’s now a screen-wide app Window instead of the traditional All Programs option, and the original alphabetical list order was replaced by a system that organized applications by program group.

The company also introduced a tile menu that replaces quick launch icons, in addition to several other changes listed by Microsoft.

In addition to a tweaked UI, Windows 8 will also perform better than the current version. According to info released by Microsoft, Windows 8 as 3 less system processes or 9 percent less and 124 MB, or 20 percent more “Available Memory.”

Security is another element that’s been tweaked up. Microsoft is going to preinstall antivirus software on Win8, much to the dislike of security vendors.