First of all, I have to appreciate Cantas, a real-time info colleboration webapp. It's built on Node.js + Socket.io + MongoDB. Powerful and simple to use are its advantages, correspondingly, complex structure and poor maintainability are its inherent disadvantages.
Fortunately, Meteor comes out for us minimalism js programmers. Let's try to refactor the Cnatas with Meteor to fullfill the same real-time features with the minimal codes.