It sounds wrong to me to refer to Apache and nginx as "alternatives" to IIS. They're the web servers, and IIS is the "alternative", kind of like how Excel is the spreadsheet application and LibreOffice Calc is the alternative. I'm aware that I cocoon myself in something of an anti-Microsoft echo chamber, though. Does reality match up to my prejudices?
At the risk of second guessing the parent, they're considering the classical 'enterprisey' stuff as mainstream. If you look at what people use in most companies of a reasonable size, IIS is surprisingly common and Apache tends to only turn up when Java or PHP is involved, with appropriate nods to Oracle and IBM for their relative technologies.
Outside on the open Internet I absolutely agree that Apache and Nginx are the default HTTP servers. I switched from Apache to Nginx years ago (with a few exceptions) as it just seemed as though I could do more with less with it and it made sense for me to standardise.
I see nginx as more a general application server, and IIS as a specialised server you run when you need NTLM/Windows integrated authentication and ASP.NET et al.
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.
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)
