That doesn't seem to be the crux of the problem, at least in this case.
We have two things going on--Realgm is sniffing for a mobile platform and not giving the user any choice, and then Onswipe isn't compatible with IE11 (so it seems, since there's an infinite loop script thing).
I edited the registry on my Surface 2 so IE11's user agent string would not show ARM. So then the user agent of my IE11 ends up showing this:
Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/7.0; Touch; rv:11.0) like Gecko
Realgm still wouldn't serve correctly. It seems to be the TOUCH part of the string that's really breaking things with the sniff. I haven't figured out how to get rid of that in the registry or if it's stored somewhere else.
Having a .reg fix would be awfully nice....
It could be the Touch. The bottom line is that is a poor web site coding and management. Nothing that MS can do about it.