Windows Vista is, after just three months of general availability, the forth most widespread operating system in the world. Windows Vista has managed to climb into the fourth position starting from September 2006, when the platform was credited with no more than 0.06% of the operating systems market.

According to data published by Market Share by Net Applications, Windows Vista increased to 0.09%, 0.11%, 0.16% and 0.18% in October, November, December 2006 and January 2007. As Vista hit the shelves on January 30, the operating system's market share exploded to 0.93% in February, 2.04% in March and 3.02% in April.

Market Share by Net Applications placed Windows XP at the top of the operating systems market with a share of 82.65%. Windows 2000 is runner up accounting for no less than 4.42% of the market and Mac OS is third with a share of 3.89%.

Up to this point, Windows Vista has made a number of victims, but Linux and MacIntel are the ones with the most weight. 0.80% is Linux's share considering the information provided by Market Share by Net Applications, while MacIntel owns just 2.32% of the OS market.

However, with the exception of Windows Vista and MacIntel that are on the rise, Windows XP, Windows 2000 and Mac OS have been constantly losing market share. Windows 2000 is down to 4.42% in April from 4.71% in March and Windows XP's market share is reduced to 82.65% from 83.57% the previous month. Mac OS has dropped from 3.94% in March to 3.89%, while MacIntel is up to 2.32% from 2.14%.

The statistics provided by Market Share by Net Applications clearly indicate the fact that both Windows Vista and MacIntel are eroding the market shares of their predecessors rather than converting each other's users. Microsoft has one important advantage over Apple with Windows Vista already on the shelves while Mac OS X Leopard was postponed until October 2007.