Reth

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.

Prysm is an Ethereum consensus client written in Go by Prysmatic Labs and historically the most used client. Validator and node operators run it to take part in consensus.

Lighthouse is an Ethereum consensus client written in Rust by Sigma Prime and one of the most used clients on the network. Validator and node operators run it to follow and attest to the beacon chain.