That's really interesting. Deserving of a top-level submission, too, I think.

May I ask what your plan is for defending lessons against cranks, crusading ideologues, and the less-than-knowledgeable once it gets more adoption? Other collaborative projects such as Wikipedia have suffered as a result of this, but I noticed in your talk that your aim is to maintain "higher" quality than Wikipedia or even Stack Exchange and Quora. I'm curious how this can be accomplished once the user base expands beyond its initial network.

Congrats on this year's IMO result!