Photospheres
The instructions for this Google Sites gadget were from https://sites.google.com/site/anynamethatisavailable/photospheres, http://photospheres.matthewsnetwork.org/home/photosphere-embedding-with-gdrive-hosting and https://googledrive.com/host/0B716ywBKT84AMXBENXlnYmJISlE/GoogleDriveHosting.html. There is some further information from Google at https://developers.google.com/photo-sphere/web/.