Hard to tell, but I'm guessing this is sarcasm.

This would definitely be possible. When GNOME say "Javascript", they actually mean Javascript + GObjectIntrospection + any C libraries that are written with Glib or libraries that have Glib bindings for them.

Javascript will end up calling C code.

Not at all. I'm quite serious. I'm actually interested to see if this could be done.

But this is very interesting :-) Can you point to any documentation?

Edit: the issue with porting LibreOffice to Javascript is the sheer size of the codebase. I don't suppose anyone has a block diagram anywhere of OpenOffice/LibreOffice that divides it into modules?

I mean, how do you tackle such a massive codebase? It looks like Michael Meeks has a good idea about this, but the biggest problem with the codebase is that there isn't any high level, quality documentation that shows how it works.

Also... and this is probably just me, but I can't even find the entry-point to the code. That's always been my issue with these apps, but that just shows my exceeding lack of ability in C++ coding I suspect.

Checkout Google Drive (former Google Docs).

Closest it probably google docs.