2009
Microsoft IIS vs. Apache / Who
Serves More?
- A study
Vijay Prasad Gupta
ECM/Web Architect

Purpose of the Study
• Back in 2007, Microsoft-IIS used to serve 50% of the
Top 20 Fortune companies (Reference: 1)
• This study was aimed to find how this has changed in
the last two years
• The study was conducted using Firefox 3.0.11 and
LiveHTTPHeaders (A firefox extension) to view HTTP
Response Headers of each of the 20 website to find out
what web server they are using (Reference: 2)

Web servers of the top 20 Fortune 500
companies for 2009
Rank Company Web Server
1 Exxon Mobil Microsoft-IIS 6.0
2 Wal-Mart Stores Microsoft-IIS/6.0
3 Chevron Microsoft-IIS/6.0
4 ConocoPhillips Microsoft-IIS/6.0
5 General Electric Sun-ONE-Web-Server/6.1
6 General Motors Sun-ONE-Web-Server/6.1
7 Ford Motor IBM_HTTP_Server/6.1.0.21 Apache/2.0.47
8 AT&T Apache
9 Hewlett-Packard Apache
10 Valero Energy Microsoft-IIS/6.0
11 Bank of America Corp. Sun-ONE-Web-Server/6.1
12 Citigroup Unknown
13 Berkshire Hathaway Microsoft-IIS/6.0
14 International Business Machines IBM_HTTP_Server
15 McKesson Microsoft-IIS/6.0
16 J.P. Morgan Chase & Co. Apache
17 Verizon Communications Apache
18 Cardinal Health Microsoft-IIS/6.0
19 CVS Caremark Apache
20 Procter & Gamble Apache
* Top 20 Fortune List: Reference 3

Graph showing the web servers of the top
20 Fortune 500 companies for 2009
Web Server of Top 20 Fortune 500 Companies (2009)
5%
10%
40%
15%
Microsoft-IIS
Apache
Sun-ONE-Web-Server
IBM_HTTP_Server
Unknown
30%

Study Results
• The data shows that though Microsoft IIS still serves the
majority of Fortune 20 companies in 2009, but it’s share
have declined by 20% (It came down from 10 to 8)
• On the other hand, Apache have gained the share by
100% (It has increased from 3 to 6). This is consistent
with the overall trends towards open source and
adoption of LAMP technologies. Note that Apache has
increased its share at the expense of both Microsoft IIS
and IBM HTTP Server
• Sun one has maintained its position as-is

References
1. Microsoft IIS vs. Apache / Who Serves More? (2007):
http://www.search-this.com/2007/06/27/microsoft-iis-vs-apache-
who-serves-more/
2. LiveHTTPHeaders: http://livehttpheaders.mozdev.org/
3. Fortune 500 List 2009:
http://money.cnn.com/magazines/fortune/fortune500/2009/full_list/