Nowadays opensource alternatives for html5 panorama viewing are at least  2: Pannellum and Panovisu !

Panovisu results of a Frenchs initiative  : not only it displays your  equirectangular or cubic panos, but you can make a complete VR tour with its java editor !

You’ll need a very recent java installation on your computer to launch it,  it has been tested on all recent browsers : all webGL activated are ok but Safari ( as far as I know)

Lets link to its website:

I can help to translate if you don’t read or speak french !


There a personal demo of mine :

Litte Vr tour in Oudon, Loire Atlantique, france

Enjoy it , let me know any bug or problem, I would back them up to its dev !