They are not porting, they have built an emulator that runs the 360 OS and then they boot the games inside of that.<p>&gt;Delving deeper, Spencer explained exactly how the emulator packages the Xbox 360 games, and how it compares to Xbox 360&#x27;s emulation of original Xbox games.<p>&gt;&quot;You download a kind of manifest of wrapper for the 360 game, so we can say &#x27;hey, this is actually Banjo, or this is Mass Effect. The emulator runs exactly the same for all the games.<p>&quot;&gt;I was around when we did the original Xbox [backwards compatibility] for Xbox 360 where we had a shim for every game and it just didn&#x27;t scale very well. This is actually the same emulator running for all of the games. Different games do different things, as we&#x27;re rolling them out we&#x27;ll say &#x27;oh maybe we have to tweak the emulator.&#x27; But in the end, the emulator is emulating the 360, so it&#x27;s for everybody.&quot;<p>&gt;Asked about whether Microsoft would require permission from game publishers to adjust game code, Spencer clarified it would not be interfering with code.<p>&gt;&quot;The bits are not touched,&quot; he said. &quot;There&#x27;s some caveats, and as always I like to be as transparent as I can be on this: Kinect games won&#x27;t work from the 360, because translating between the Kinect sensors is almost impossible.&quot;<p><a href="http:&#x2F;&#x2F;www.gamespot.com&#x2F;articles&#x2F;revealed-how-xbox-one-can-play-360-games-via-backw&#x2F;1100-6428366&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.gamespot.com&#x2F;articles&#x2F;revealed-how-xbox-one-can-p...</a><p>I also remember watching a video where they talked about it, it had some more details. I can&#x27;t remember what it&#x27;s called though and I couldn&#x27;t find it with a cursory search.