Three.js - https://threejs.org demo
Panolens.js+Three.js - https://github.com/pchen66/panolens.js demo
360-image-viewer - https://github.com/Jam3/360-image-viewer demo
Kaleidoscope - https://github.com/thiagopnts/kaleidoscope demo
Panellum - https://github.com/mpetroff/pannellum demo
Photo Sphere Viewer - https://github.com/mistic100/Photo-Sphere-Viewer demo