The BBC is launching it's own 360 degree player.
This first iteration displays the 360 video in the 'magic window' style, allowing the viewing window to be moved in all directions using a mouse, or finger for touch devices. Future versions will include full headset support and improved Apple and mobile support (including iPhone and Safari desktop which are not currently supported).
We will also aim to support 'dynamic audio' in which audio responds to the direction a headset is pointing in. This requires support for 4, 8 or even 16 channels of sound, but can be very powerful in the creation of a fully immersive space.
The experience of building a 360 player has taught us a lot about equirectangular projections and other interesting 2D to 360 degree mapping trigonometry which isn't usually required when presenting conventional 16:9 video!