An emulator that plays only one game isn't really an emulator is it.
Xeon is more of a shell for Halo than a true emulator and Cxbx can't even be called an emulator as it loads code ( allegedly) but doesn't do anything with it.
You can't see it, play it, manipulate it etc.
It's nice to see some action in this area but folks are being a bit premature in announcing that there is a successful Xbox emulator just yet.
I tried Xeon and it threw up a dll error.
I never get them when playing Halo on my Xbox.