But for how long?
[Update: Twitter user @thisoldconsole has reported issues getting the emulator to operate. Alongside that, YouTube user SpitfireSpud has released a video demonstrating the overall instability of the application.]
[Update 2: Microsoft has quietly removed the application from the Xbox One store. If you go to the application page now, you'll notice that the console no longer appears on the list of compatible platforms. Anyone who has previously purchased the application will still be able to use it.]
Earlier this month, NESBox, a NES emulator that was to be released on the Xbox One, passed certification for sale on the console's storefront. This would have allowed it to be purchasable on the platform without the need to modify the console's system software. While the certification was eventually revoked prior to the software's launch, it was interesting to see such a program get so close to having an official release on a modern gaming console.
It looks like Microsoft was too distracted with NESBox to notice that a Nintendo 64 emulator had managed to sneak past certification and make it on to the Xbox One's store.
Win64e10, which is a modified version of the Nintendo 64 emulator Mupen64plus and was previously available for Windows Phone and Windows 10, now features Xbox One compatibility as of its most recent update.
Considering the highly litigious nature of Nintendo, as well as the fact that Microsoft currently publishes several ports of Nintendo 64 titles with the Rare Replay collection, I do have to wonder how much longer Win64e10 will last on the Xbox One storefront.
I guess it's always possible for the developers to convert the emulator into a HTML5 application that's compatible with the Xbox One's web browser, should Microsoft decide to take it down. It wouldn't be the first time such a thing has happened.
Win64e10 [Microsoft Store]