In the August 2009 survey we received responses from 225,950,957 hostnames — 13.7M less than in July.

Much of the drop this month is due to the expiry of a large number of sites at The Planet, including 5 million sites in the .pl top-level domain all on one IP address, which were believed to be part of a linkfarm.

Lighttpd had a significant gain this month, rising to over two million sites, just under 1% of the survey. Lighttpd is a webserver designed for high performance environments. It has a small memory footprint, a large feature set and is licensed under a revised BSD license. Originally written by Jan Kneschke, Lighttpd is now maintained by a small team of developers, and now hosts a large number of popular and high traffic sites, including mininova.org and the controversial Pirate Bay.

Apache.org has been offline for 3 hours this morning, after one of their servers was compromised. Their sites were displaying the message:

The message goes on to say that the compromise is "not due to any software exploits in Apache itself", but was instead due to a compromised SSH key.

Update: Most of apache.org's sites have been back online this afternoon after they switched over to servers not compromised in the attack. Apache have released more information about the incident: an account used for backups was compromised on a back-end server. This server distributes content to Apache's public web servers, so the attackers used it to distribute scripts to the web servers; once the scripts were public, the attackers could execute them remotely, gaining access to the web servers as well. But these rogue processes were detected, so the servers were taken offline for investigation and clean-up.

Web.com, New York Internet, Virtual Internet and Hosting 4 Less had the most reliable hosting company sites in July 2009, with each site only failing to respond to a single request from our performance monitors.

This is Web.com's first appearance as joint number one. Web.com is the only company in this month's top ten whose site is served by Microsoft IIS/5.0. Web.com offers a variety of Linux, Windows and eCommerce hosting packages, as well as managed email and domain name registration, and web design services.

This month is New York Internet's fifth at the top of the table this year. They also made the number one spot in January, February, April and May. New York Internet offer colocation, dedicated servers, disaster recovery, web hosting, E-mail, DSL access and managed services.

This is the second month this year in which Virtual Internet has been joint first, and it has stayed in the top ten since April. Virtual Internet offer managed and cloud hosting as well as managed messaging and collaboration services.

Hosting 4 Less are one of the most reliable hosting companies for the third time this year, after coming joint first in March and April. Hosting 4 Less are based in California, and offer web, FTP and eCommerce hosting. They also run backup4less, an online backup service.

This month's top ten sees three company sites using Windows (including Windows Server 2008, 2003 and 2000), as well as three running FreeBSD and two running Linux.