[foms] WebVTT implementation in browsers

[Thomas Levine]

I have found the discrepancy between the draft specification and the
actual implementation to lead to ample disappointment, so I appreciate
any reconciliation. The main feature that I really wish would be
implemented is karaoke display. I don't use polyfills, but I am
rendering my WebVTT files differently to cope with the lack of karaoke
display. I would render them with ordinary karaoke timings if that
worked in browsers.

You remind me, I still haven't gotten around to writing up the opinions
I developed over the past year about the language settings in the WebVTT
specification and in the HTML track tags. I have been working on a
project with subtitles in many different languages, and the modeling of
languages is inappropriate for my use. Once I write up these opinions,
do you want me to post it on this issue tracker?
https://github.com/w3c/webvtt/issues