This looks promising, I've been working with the Emscripten[1] port of eSpeak and porting it to the browser and node.js [2] as a contributor (not author)

[1]: https://github.com/kripken/emscripten

[2]: https://github.com/christopherdebeer/speak.js

I'm curious how best one could participate/contribute to spec drafts like this, seems it's being steered by Google at the moment.