Besu

staking-deposit-cli generates validator keys and deposit data for Ethereum staking, and is now maintained as the EthStaker fork that the original owners point to. Validators run it once when setting up new keys.

Reth is a modular Ethereum execution client written in Rust by Paradigm. Rust builders run it as a node or extend its components to build custom infrastructure.

Erigon is an efficiency-focused Ethereum execution client that embeds the Caplin consensus layer. Infrastructure builders run it when they want one process for execution and consensus and fast access to historical state.