From farmboynick:
I have just launched XBMC for Xbox1 on my Xbox360, it was so simple … I patched Avalaunch(info) to boot from disk with a halo title id and put a XBMC folder on the disk. After Avalaunch booted I went to file manager and copied the XBMC folder to the E-drive, then simply clicked the XBMC XBE file and it worked.
So far I have been able to launch all XBMC versions that I have tried and can also launch surreal64 and some xbox1 games in file form from HDD. All from selecting the XBE in the Avalaunch file manager
Some versions of XBMC can run picture files, some can run music files, so far I can't get AVI movies to play or gain network access.
Original Source: Xbox-Scene