IIS vs Apache

The Microsoft whitepaper (Word document) "Comparing IIS and Apache: Questions and Answers" published in March 2009 has interesting counter arguments on the long raging debate on which of the two is better. It answers the following questions -

1. Does IIS offer the performance and scalability I need?
2. Is IIS as secure as Apache?
3. Is IIS harder to manage than Apache?
4. Is IIS as reliable as Apache?
5. Is IIS really as modular as Apache?
6. Apache is an innovative platform. What about IIS?
7. Troubleshooting Web applications can be complicated. What does IIS offer to simplify troubleshooting?
8. I depend on a wide variety of Web architectures. Can I run them on IIS?
9. Yes, PHP applications can run on IIS, but is it really a good idea?
10. Will IIS be more expensive than Apache?

Also check Bill Staples' views on this topic.

Based on a survey of 205+ million sites, Netcraft reports that Apache has a 54% share in July 2010 while IIS has 26%. As a poster on Channel9 says, this may not be the true measure of popularity as it counts sites & not servers. The results could be skewed because domain registration & hosting sites park thousands of sites on one instance of Apache.

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