Could h5p.org host an embeddable Etherpad installation?
I already use Etherpad Lite on my site so this isn't particularly for me but could be great for h5p.
Live document collaboration, a tonne of modules and WebRTC video chat that somewhat replaces appear.in. You could run multiple versions so that video was just an option.
Since Etherpad requires Nodejs and some setup beyond a typical h5p installation, I thought that h5p.org could host it instead. I'd even consider hosting it since it's pretty light.
Just an idea.