CXBX is not your typical emulator, while many would classify it as an Xbox Emulator the actual goal of CXBX is a bit more complex. The program intends to actually convert the Xbox file, into a fully working Windows executable, while it seems like a far fetched idea it is fully plausible considering how close the Xbox’s architecture is to Windows.
Unlike other emulators that are fully custom solutions, Microsoft used a lot of there experience developing Windows to help develop the Xbox and its architecture.
Overall compatibility from CXBX is pretty bad, most games will refuse to work, and those that do will either be extremely slow or riddled with all sorts of bugs. Despite this though CXBX is one of the more promising attempts at getting the Xbox games to run on other platforms. But sadly, development seems to be all but ceased, and now there is only one real promising emulator that is left in development. That being XQEMU.
Please note for those who are on 64-bit systems, CXBX may not run at all due to the way it converts the executable, it was designed before 64-bit became mainstream.