Vitalik's annotated eth2 spec. Not intended to be "the" annotated spec; other documents like Ben Edgington's https://benjaminion.xyz/eth2-annotated-spec/ also exist. This one is intended to focus more on design rationale.
Collection of RESTful APIs provided by Ethereum Beacon nodes
Specification for the external block builders.
Collection of APIs provided by Ethereum execution layer clients
An Ethereum-compatible smart contract parachain on Polkadot
🌟 TypeScript Implementation of Ethereum Consensus
Ethereum Proof-of-Stake Consensus Specifications
provides metadata for chains
Official repository for specifications for the Portal Network
Common tests for the Ethereum proof-of-stake consensus layer
Ethereum peer-to-peer networking specifications
Agent-based simulation environment for PoS Ethereum
Specification for the Execution Layer. Tracking network upgrades.
Ethereum network merged right from genesis