In the January 2009 survey we received responses from 185,497,213 sites, reflecting an uncharacteristic monthly loss of 1.23 million sites.
Apache's market share grew by more than 1 percentage point this month, extending its lead over Microsoft IIS, which has fallen to less than a third of the market. In total, Apache gained 1.27 million sites this month.
Microsoft showed the largest loss this month, after more than 2 million blogging sites running on Microsoft-IIS websites expired from the survey.
GFE, which is primarily used by Google's Blogger service to publish blogs under the blogspot.com domain, lost nearly 600 thousand sites, while nginx continues to grow and increases its market share to 1.87%.
Further down the field, the number of sites hosted on httpd and WebserverX both increased by more than 20%. Both web servers take a relatively small share of the market, however, with httpd growing to 236 thousand sites and WebserverX growing to 154 thousand.
June 2000 - January 2009
A more detailed list of servers is given here.