node.js + IIS on Windows

Here is a brief summary why Microsoft supports node.js (and PHP, and Hadoop, etc)

Installing and Running node.js applications within IIS on Windows - Are you mad? - Scott Hanselman

" The IIS folks, the Windows folks, the Azure folks, want to make sure everything runs well on Windows. Remember, we sell Windows, so it's good if it does many things well. ;)"

Makes sense. node.js currently resembles early days of Ruby-on-Rails,
and many of web frameworks used today are influenced by "opinionated" nature of Rails.

How about performance?

ScottH Hello World test:

node: 10,000 hello worlds a second and ended up with just under a million normal requests and responses in 90 seconds

ASP.NET: IHttpHandler doing the exact same thing on this same machine gets 22,500 requests a second, so node and iisnode has some room to improve...

For complete comparison memory and CPU usage would also need to be considered...