Well, this is a turn-up for the books: Microsoft has certified a NES emulator for the Xbox One. If you have the app installed you can load up a USB with ROMs and play Nintendo games on your Xbox. That would be illegal, of course, but it can be done.
— nesbox.com (@nesboxcom) September 9, 2016
The NESBox app is already available on Windows phones and can be downloaded for your PC through the Windows Store, but having an app on a console that can potentially play another console manufacturer's games could cause a little friction for Microsoft.
NESBox isn't purely for playing emulated versions of Nintendo's back catalogue. You can use the virtual console to make games in the app. According to the itch.io page, "there are built-in tools for development: code, sprites, maps, sound editors and the command line, which is enough to create a mini retro game."
Again, loading up a USB with NES ROMs and playing them on your Xbox One would be illegal. Nintendo is very clear about this and has a long FAQ about the use of ROMs and emulators to play its games.