NETCRAFT
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Four of the 10 most most reliable hosts run their web sites on Windows, two on Linux and three on FreeBSD.


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In the July 2007 survey we received responses from 125,626,329 sites, an increase of 3.62 million sites from the June survey. Recent trends hold steady this month, with the Internet's strong growth continuing apace and Microsoft making additional inroads into Apache's leadership in web server market share. The web has grown by 20.4 million sites thus far this year, slightly behind the growth rate from 2006, when the survey added a record 30.9 million sites.

Microsoft adds 2.4 million sites this month, pushing the total number of sites running on Windows servers past 40 million, and helping Microsoft improve its market share by 1.01% to 32.8%. The open source Apache server has an increase of 556K, and slips back 1.11% to 52.65%. Google gains 592K sites this month, and now has 4.35% share.

In active sites, Apache is now at 49.98% share, less than 14.5% ahead of Microsoft. While that's still a considerable lead, Apache had a 33.4% advantage at this time last July, meaning Microsoft has cut its deficit in half in the past 12 months.
July 2007 Web Server Survey

I won't take the time to try to go find the post I made before but I told you that
Microsoft will increase their Web Server foothold in time.