Similar to how Apple takes ~75% of the handset market profits, IIS takes almost all the profit in the web server market and is increasing revenues year after year.
It does quite well for itself given that the competition is fierce and free.
If you apply a set of criteria then that is the result.
The more interesting metric (though hard to quantify) is how much is earned with software.
http://www.zdnet.com/blog/stewart/adobes-q1-financials-show-...
I would think ASP.NET/C# would make the most profits in the dynamic web language space.
My point being that CF has a license, whereas Ruby and Python do not - which has little value in gauging success, a la IIS v Apache/nginx. (Ignoring the reality of open source Railo and Open BlueDragon for the moment)
They also both have licenses, but they don't charge money to obtain a copy.