The old Announcement discussion thread on the need for help with the HTML 5 player is deleted / locked / broken.
https://scratch.mit.edu/discuss/topic/19132/

Is there any update on the official HTML 5 player?

Phosphorus was working great, then it broke badly, then it works again a bit. Is the Scratch team working with the Phosphorus developer/s?
http://phosphorus.github.io/

With Flash on the way out, Phosphorus and Pixie seem like the best way to go. With so many kids learning Scratch, I am surprised significant effort is not being pushed into some HTML 5 player.

You'll be happy to hear about the great projects the ST has in store: https://scratch.mit.edu/developers