Xbox 360: What OS is it running?

Found an article at WindowsforDevices.com linked on /. concerning what OS the Xbox 360 is running. In order to spare you a bunch of Linux-based quasi-religious zeal, here’s the pertinent info:

The original Xbox ran an OS that had its roots in Windows 2000. Granted, by the time you strip out everything that is not needed in a console like the Xbox and replace some of the parts with stuff specific to that device (like the file system), and add a few pieces, it hardly resembles anything remotely like Windows 2000 at all. But you could say that’s where its original roots lie, even if 95 percent of it has been cut or heavily altered.

The Xbox 360’s OS, in turn, has its roots in the OS of the original Xbox. I’ve been told (not by Microsoft, but by one of its hardware partners) that the Xbox absolutely positively does NOT run Linux [oops, the censors missed that one –Ed.] or Unix or some variant of that. The Xbox 360 project started with the Xbox OS the same way the Xbox project started with Windows 2000. They cut, added, and changed it in both large and small ways. It’s now quite a bit different from the Xbox OS, which was itself quite a bit different from Windows 2000.

Really, the best way to think of it is as “The Xbox 360 OS.” But if you really have to think of it in Windows terms, you could say it has roots in Windows 2000 by way of the original Xbox, albeit with sweeping changes along the way.

Interesting, if somewhat useless knowledge. (Unless you’re part of the mod community, that is.)