What makes you say that? Looks like PHP/Apache running on Linux: http://uptime.netcraft.com/up/graph?site=http%3A%2F%2Fwww.qu...
"Q: Why is Qimo4Kids.com running on Windows and .Net? A:Both the design and hosting for this website is being donated to us by TMR Agency. While they are not a Linux shop, they wanted to be involved in helping us get educational software to kids in the capacity they could. We are extremely fortunate and grateful for the amount of design and development effort they put into our website, as well as their continued hosting space and bandwidth."
I mean, you can of course play with MIME types and serve arbitrary file extensions, but why would you want your Linux distro to seem as though it was served by IIS?