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You can use this page to email Kyle Simpson about You Don't Know JS Yet: The Unbooks.
About the Book
You Don’t Know JS Yet: The Unbooks is a special, draft-edition release collecting the final remaining content from the second edition of the You Don’t Know JS Yet series. It includes the complete, previously unpublished drafts of Book 3: Objects & Classes and Book 4: Types & Grammar—books that were written in full but never formally edited or released for publication.
These chapters reflect the same in-depth exploration and care you’ve come to expect from the series, just presented here in their raw, unedited, unpolished form. They’re readable, structurally complete, and technically solid—offered honestly as-is.
This release also includes two bonus chapters on the “lost” volumes that were never written: Book 5: Sync & Async and Book 6: ES.Next & Beyond. These reflective essays explain what those books were meant to be, why they were ultimately abandoned, and what insights remain worth sharing. This is a project for the completists, the curious, and anyone who still cares deeply about understanding JavaScript, not just using it.
About the Author
Kyle Simpson is a web-oriented software engineer, widely acclaimed for his "You Don't Know JS" book series and nearly 1M hours viewed of his online courses. Kyle's superpower is asking better questions, who deeply believes in maximally using the minimally-necessary tools for any task. As a "human-centric technologist", he's passionate about bringing humans and technology together, evolving engineering organizations towards solving the right problems, in simpler ways. Kyle will always fight for the people behind the pixels.