This looks really interesting and potentially very useful. I skimmed the docs and took a look at the source code. This is no small project. I could not find a high level doc about how it works, though. There seems to be contenteditable element as a user events (writing) receptacle from which it generates appropriate DOM manipulation. Since ODF is a complex format, the XML is complex too, so probably editing elements directly won't be feasible.

There is even a desktop version. I'd really like to try if this could work as a LightTable plugin. Code looks like straight forward JavaScript and it's build with Google Closure, like LT is. I'll how to dive through the code at some point and see how hard it could be to support different XML formats, like DocBook.