DataPipe, Navisite, MyHosting.com and iWeb8 are the most reliable hosting companies for March 2007, followed closely by New York Internet and Webfusion. This marks the first time in the top spot of our monthly rankings for NaviSite and My Hosting.com, although each have been among the top 10 a number of times. DataPipe has been the most reliable host fives times previously, while iWeb8 was the top performer in January.

NaviSite is a managed hosting company in Andover, Mass., that also provides content distribution services. Navisite is publicly held, and was among the best performing U.S. stocks in the infrastructure sector in 2006, when its shares rose 457 percent. It has 950 customers in 14 data centers in the US, UK and India.

MyHosting.com is the hosting arm of SoftCom Technology Consulting, which also operates the mail2web email service. MyHosting.com is based in Toronto, Canada and was founded in 1997. The company specializes in hosting on the Microsoft platform, but added Linux hosting in 2004.

Three of the 10 most most reliable hosts run their web sites on Windows, fiveon Linux and two on FreeBSD.

Microsoft's latest security updates include a patch for a security hole in Microsoft Content Management Server (MCMS) discovered by Netcraft's Martyn Tovey. Microsoft update MS07-18 addresses two issues in MCMS, including a cross-site scripting and spoofing vulnerability that was reported to Microsoft by Netcraft.

"The vulnerability could allow the injection of a client-side script in the user's browser," Microsoft notes in its summary. "In a Web-based attack scenario a compromised Web site could accept or host user-provided content or advertisements which could contain specially crafted content that could exploit this vulnerability. The script could take any action on the user's behalf that the Web site is authorized to take. This could include monitoring the Web session and forwarding information to a third party, running other code on the user's system, and reading or writing cookies."

Microsoft Content Management Server allows developers to build complex web sites atop the .NET framework, and is typically used to manage enterprise portals and e-commerce sites. Many of the functions of MCMS 2002 have been integrated into Office SharePoint Server 2007 product. MCMS continues to be widely used, and was found on more than 5,000 sites last year.

Netcraft provides a Web Application Testing service that rigorously tests the defenses of Internet networks and applications. It is part of the Audited by Netcraft service, which provides a range of advanced Internet security tests.

Hostway Corporation has acquired Affinity Internet Inc. in a deal that will combine two U.S.-based hosting operations focused on the business market, the two companies announced today. Hostway CEO Lucas Roh will lead the combined entity, which Hostway said would have 600,000 customers, 750 employees and a presence in 11 countries. Terms of the deal were not disclosed.

The acquisition was described as "the conclusion of a long and involved process that took many months," and will provide Hostway with the scale and breadth of services to compete in a changing hosting landscape. Affinity operates multiple hosting brands, including ValueWeb, Gate.com and BigStep.com, and also offers private-label hosting programs for third-party clients including eBay.

The deal will give Hostway more than 553K hostnames, plus additional sites from Affinity's private-label hosting, placing the combined entity among the world's 30 largest hosting providers, according to Netcraft's Hosting Provider Switching Analysis.

“By joining forces, we have an increased global scale, scope, human capital and financial strength to continue to deliver superior service levels and innovative products, which Hostway and Affinity have both built valuable brands and reputations on," said Roh. "Our first and main focus through this acquisition has been to ensure that customers of both company’s do not experience any disruption in current services and in fact bolster it further."

An open source initiative to reverse gains for Microsoft web server software appears to be using edited server headers to try and improve the showing of the Apache web server. Sites using the Open Source Parking service report that they are running on Apache, but appear to actually be hosted on lighttpd. Both Apache and lighttpd are open source web servers, but Apache leads in the Netcraft survey with a 59 percent market share, while lighttpd is a newcomer with just 1.2% share.

Open Source Parking was formed last year by Linux evangelist Bruce Perens to counter a 5 percent market share gain by Microsoft in the April 2006 survey, when domain registrar Go Daddy shifted 4.5 million parked domains from Linux to Windows Server 2003. The project's goals are to increase the market share for open source software and generate revenue from advertising on the parked domains to fund political efforts on behalf of the open source community. While parked domains can be challenging to track accurately, there is no evidence that the effort has made any impact on web server market share.

Open Source Parking is not the only site to intentionally alter server headers, with security concerns cited as a motivation in some instances. The issue for Open Source Parking appears to be that Perens prefers lighttpd, but many open source supporters view Apache's stats as the key metric in the market share battle with Microsoft servers. The possibility that Open Source Parking would use fake Apache headers was discussed by Perens shortly after the project was announced.

In the April 2007 survey we received responses from 113,658,468 sites, an increase of 3.2 million sites from last month's survey. Apache continues to be the most widely-used web server, powering more than 66.9 million sites, compared to 35.3 million sites using Microsoft server software.

This month the Web Server Survey adds public tracking of lighttpd, an open source server designed for high-performance sites that has been gaining popularity in recent months. Lighttpd is currently detected on 1.38 million sites for a 1.2% share of the web server market, well ahead of Zeus and moving up quickly on Sun. Lighttpd has a relatively small memory footprint and is optimized for a large number of parallel connections, which has made it popular on sites using applications based on AJAX or Ruby on Rails, or hosting environments for virtual private servers.

Popular sites using lighttpd as their primary server include the SourceForge developer community, the social media hub Reddit and the instant messaging service Meebo, while YouTube and Wikipedia use it to serve parts of their sites.