Apache vs. IIS, which one is most popular?

If you develop web applications, you are probably aware of the market share of different web servers, at least to some extent. For years, I guess since world wide web has existed, the Unix based Apache has been the web server. But times are changing, it seems, and IIS is gaining market share.

Now, according to latest market research, Apache is still number uno with about 48% share, but Microsoft Internet Information Server is the second most popular, at 34%. Pretty good in my opinion. But IIS 6 and soon-to-be-here IIS 7 (on Windows Server 2008, that is) really are good web servers, you cannot argue that. Especially for ASP.NET web applications which my apps are.