So excited for this, really excited to dig in and start kicking the tires. One question, since it looks like steeleduncan is answering questions in here: How does the realtime typesetting deal with large documents? I can't tell if it can keep up because it's only re-calculating a segment of the total document, but I've been working with LaTeX mostly for book-length documents; my chronic annoyance is the minute-plus compile times unless I break it up and only compile a chapter or two at a time. A realtime option would be a huge benefit for the final typesetting runs where I'm trying to fix image placement and orphans and whatnot, but I don't know if that's asking too much of the engine.