Here's a bit more about how we did this https://medium.com/@gpitfield/gitlance-how-we-ranked-9-milli...

In short, it's a graph that uses repo forks, stars, and commits to generate a big graph, and a PageRank-ish algorithm to generate the rankings.

Super cool to see TJ (creator of express) in the number 1 spot. I think he's mostly writing Go these days, but express is still massively popular.