// the find
getify/You-Dont-Know-JS
A book series (2 published editions) on the JS language.
The 'You Don't Know JS Yet' series by Kyle Simpson is a free, openly-readable book series covering JavaScript's core mechanics in depth — scope, closures, objects, types, and the prototype system. It's aimed at developers who use JS daily but have gaps in their mental model of how the language actually works under the hood. The second edition is largely complete, though two planned titles were canceled.
The scope and closures book is genuinely one of the best technical treatments of lexical scope, the TDZ, and closure mechanics in any format — it corrects misconceptions that persist even in experienced developers. The writing is precise without being academic; Simpson will tell you when MDN is misleading or when a common pattern is subtly broken. The whole thing is free to read on GitHub, which removes every barrier to entry. Eleven years of community error-reporting means factual mistakes get caught and fixed.
The series is now closed to contributions and two of the originally planned volumes — 'Sync & Async' and 'ES.Next & Beyond' — were canceled, leaving real gaps if you came here specifically for those topics. 'Types & Grammar' is still a rough draft, so the chapter on coercion (historically the most contentious and misunderstood part of JS) isn't finished. The first-edition books covered ES6 features that feel dated now, and while the second edition addresses this, the canceled volumes mean you won't find async/await or generators treated with the same depth as closures. Not a problem for a book, but the repo itself has no runnable code examples — everything is prose.