This is an interesting library to watch for sure. Personally I have built many scrapers and extractors to be used in house and I have spent many hours on tweaking Readability JS and I know how complicated and hard-to-test the code is. Seeing how Fathom does its job is cool -- it takes care of a lot of the low level, bookkeeping parts so that all you need to do is to focus on tweaking the ranking formula. I'm not surprised if in the future we will have a shared repo containing "recipes" to parse pages, and slap on a nice UI with DOM traversal then we'd have a Kimono-like app for parsing contents.