According to Netcraft it appears that Microsoft has been closing the gap between them and Apache over the last year and a half. This months web server survey reveals that Apache’s market share is now below 50% (48,4%) while Microsoft is at 34,2%.

Market Share for Top Servers Across All Domains August 1995 - August 2007

The open source Apache has been the leading web server software since the March 1996 Netcraft Web Server Survey. In November 2005, Apache was found on 71 percent of web sites, putting it more than 50 percentage points ahead of Microsoft IIS (20.2 percent). At the time, Apache’s market share advantage seemed insurmountable. But less than two years later, Microsoft has narrowed that 50 percent gap to 16.7 percent. The margin is even tighter in active sites, where Apache leads Microsoft by just 12.2 percent.

Apache’s lead remains substantial in both categories. It’s worth noting that Apache has lost market share to another open source server, lighttpd (1.2% of all sites), and Google (4.4%) as well as Windows. But if Microsoft continues to gain share at its current pace, it could close the gap on Apache sometime in 2008.

The survey doesn’t take global variations into account, which probably would give a slightly different picture. It’s a known fact that in Asia Microsoft’s IIS web server are overrepresented, mainly due to software piracy according to Google. The lack of software patches and updates not available for pirated versions of IIS allows for inclusion of malicious software, which in turn affects the overall statistics. In Western Europe and the US the numbers are reversed.

It will be interesting to see how the trends develops when Microsoft’s 2008 server edition hits the market…