It's like Google Maps, but you're inside the earth pinned at the center and the images are projected onto the sphere. They load in tiles, so it's trivial to get it to be this fast.
Sure you may publish a JS library on NPM to prove it is sooo simple?
Features:
- Equirectangular, partial, cubic, and multi-resolution panoramas
- WebGL and CSS 3D based renderers
- Hot spots / tours
- Compass headings
- Plug-in free
- Framework free
- Video support