One recurring problem in creating real-time web applications is how to sync the display between browser windows/tabs amongst different users (and of the same user).
Duplicating template code increases complexity while removing duplicate code using client-side-only templates hurts SEO. This is the problem that Quora solved. Instead of streaming compact JSON data, Quora streams rendered HTML that updates any part of the page (not just a section of the page).
From an answer Charlie wrote: "If I were making a new website from scratch without LiveNode, the first thing I would do would be to rebuild LiveNode. Pretty much everything about web development is easier and faster and more correct using it." 
One of Abert's (Quora Engineer) tweets: "Going back to Django after having used Livenode is just painful."