I think maybe Wikipedia is better here than Wolfram's site, it has entries for Ramanujan graphs and expander graphs for example. The paper does actually seem r

I think maybe Wikipedia is better here than Wolfram's site, it has entries for Ramanujan graphs and expander graphs for example. The paper does actually seem readable, especially at the beginning, but it's dense and long. Somewhere between the article and the paper in terms of complexity and technicality would definitely be interesting to me, although I realise it's a lot of work to produce something like that. Interestingly the paper acknowledges collaborators who have helped via MathOverflow. I wonder if a collaborative site for explaining maths papers in more detail could be viable. After all, even xkcd.com has explainxkcd.com. Like you, I am not sure what this would like, but it would be fun to find out.