The book isn’t due for publication by O’Reilly until Q4 of this year, but content and progress is publicly available on GitHub today. Here’s the skinny:

a book for developers, offering a guide to the operation and use of the Ethereum, Ethereum Classic, RootStock (RSK) and other compatible EVM-based open blockchains.

Co-authored by Andreas Antonopoulos and Gavin Wood, Mastering Ethereum has a high chance of being excellent. 👌