It is always interesting to see how various kinds of statistics of Web server market shares come to totally different results. This leaves room for everyone to choose which statistics just suits them best or is to their own liking [1] [2]. In this post, I compare four prominent statistics (Netcraft, Google, Port80, Security Space) with respect to the market shares of IIS and Apache.

I rounded the numbers and compared different months. Considering the huge differences between those statistics, this doesn’t matter anyway.

Ogranisation / Web Server Apache IIS
Google (June 2007) 66% 23%
Netcraft (October 2007) 48% 37%
Port80 (July 2007) 25% 55%
Security Space (September 2007) 74% 19%

Of course, the different results are due to different counting. However, all organizations claim that their numbers represent the Web server market shares. Netcraft seems to count every domain, Google excluded domains without root URL, Security Space only counts domains with backlinks, and Port80 only includes Fortune 1000 companies.

The Netcraft data includes tons of parked domains. Security Space tries to avoid this fallacy by including only domains that someone found interesting enough to link to. They claim that they exclude personal web sites this way which certainly is doubtful. I suppose their data contains mostly personal blogs. Google’s method probably excludes many professional sites, because only they work with redirects.

In my view, the data of Port80 is the only one where the word “market share” really makes sense, since they only count corporate sites where someone deliberately chose the Web server software. If you just count domains you inevitably include myriads of bloggers who don’t even know what Web server they are using.

However, it is also obvious that very big companies (IBM and Google excluded) tend to prefer commercial software over Open Source. I suppose that the market share of Apache is much bigger among mid-sized and smaller companies. Yet, most interesting is that Apache gained ground among Fortune 1000 companies. Last year Apache only had a market share of 20% in this field. This corresponds to an increase of 5% compared to 2007. I think this is due to the fact that Open Source content management systems are getting more and more powerful.

The recent rise of IIS in the Netcraft survey shows that Microsoft’s strategy to add more features for hosting companies is quite successful. Presumably, this didn’t increase their market share significantly, but it is quite helpful for marketing since the Netcraft study is the one most often cited. In the future, Microsoft will certainly try to convince developers of Open Source content management systems to move to the Windows platform. The better support of PHP in IIS7 is already one step in this direction.

Anyway, what is your favorite IIS-Apache market share statistics? I guess there are countless ways to interpret the differing numbers.