Microsoft IIS has faced a long uphill battle in its attempt to grab users and mind share from market leader Apache, the open-source Web server that is a favorite in UNIX shops. In the summer of 2000, a Netcraft survey touched off a war of words between rival Windows NT and UNIX camps, each seeking to prove the superiority of its favorite product. The Netcraft Web Server Survey (http://www.netcraft.com/survey/) showed Apache dominating IIS—serving up more than 10 million sites by midsummer. Sixty percent of Netcraft's 15 million surveyed sites use Apache, and IIS is a distant second with only 21 percent of the market; iPlanet (formerly owned by Netscape) comes in third with 7 percent.

However, the Netcraft survey didn't categorize the surveyed sites, which might largely consist of personal and enthusiast sites. This lack of detail prompted ENT Online to survey Fortune 500 companies to determine which Web servers they use. ENT argues that its survey is more meaningful because it omits home-based systems, enthusiasts, experimenters, and smaller commercial sites that might be short-lived.

ENT's results were much different from Netcraft's. According to ENT's survey (http://www.entmag.com/displayarticle.asp?=6150060853), IIS is the most commonly used Web server among the Fortune 500, with 41 percent of the market. iPlanet Web server is second with 35 percent, and Apache brings up the rear with only 15 percent of Fortune 500 deployments. In the top 100 companies, 58 percent of Web servers run iPlanet, 25 percent run IIS, and only 10 percent run Apache.

After online shouting matches at popular Web-based watering holes such as Slashdot, the online magazine Apache Today decided to survey the 30 most-popular Web destinations according to Media Metrix (http://apachetoday.com/news_story.php3?ltsn=2000-07-27-001-01-NW-LF-MR). Apache came out on top with 33 percent, iPlanet came in second with 24 percent, and IIS came in third with 21 percent.

"Obviously, this isn't a slam dunk for Apache," said Apache Today's Kevin Reichard. "Nor was anyone at Apache Today expecting it to be. But the trends exhibited by the top 30 Web sites in terms of popularity should end any talk about the momentum of IIS in the marketplace, and it should also point out the amazing popularity of Netscape servers."

Despite Reichard's dismissal, IIS seems to be holding its own. Web juggernaut Lycos (fourth on Media Metrix's list of most popular sites) recently adopted Windows 2000 and IIS, and two of the top four sites—Microsoft and Lycos— now use IIS. In addition, many popular Web destinations (e.g., eBay, GO.com, AltaVista, InfoSpace) are built, at least in part, on a Microsoft Web platform.