Upgrading Ethereum

This is a work-in-progress technical handbook, also called "The Eth2 Book," on Ethereum's move to proof of stake and beyond. Its editions follow the names of Ethereum consensus layer upgrades: Edition 0.1 is Altair, Edition 0.2 is Bellatrix, and Edition 0.3 is Capella, which is the current work in progress. The latest version is always at eth2book.info/latest, and earlier editions are frozen as they were published. The source material is available on GitHub, and a PDF version is also offered.