With further testing, I have a thought about the failure of the XMLHttpRequest on my local Desktop machine where I double click on the HTML file that contains the XMLHttpRequest: I think it relates origin policy violation caused by the URL on the HTML file being a disk (file:///D:/Documents and Settings/) and the request URL for FuseGL's XML data being "http://localhost:42422".
That doesn't answer the "Bad Request - Invalid Hostname" when accessing the Window 8 public domain with port ":42422" problem, but it eludes to verification of my concern about "origin policy violation when I attempt to access FuseGL's XML output from a web page served by the Apache server" with the additional problem that the Windows 8 Apache server has an URL-IP 108.xxx.xxx.xxx and FuseGL's URL might look like 192.xxx.xxx.xxx.
Even if that takes care of itself depending on access from the public internet or access from the local network, I remain concerned that there will be a violation when the code from the Apache served page attempts to access the XML served by FuseGL.
Wonder if there some aliasing available in the Apache configuration.
Guess I have to wait to get to the Windows 8 machine.