Prysm

Stereum is a GUI-driven installer for syncing Ethereum and Optimism nodes locally and exposing your own JSON-RPC and websocket endpoints once blocks are current.

Besu is a Java Ethereum execution client hosted by LF Decentralized Trust, formerly under Hyperledger, with wide enterprise use. Node operators run it when a deployment is standardized on the Java stack.

Teku is a Java Ethereum consensus client from Consensys that is favored by institutional operators. Validator and node operators run it when a deployment is standardized on the Java stack.

Ream is a Rust implementation of Ethereum's proposed Lean Consensus design. Client developers use it to experiment with the next consensus architecture, and it is not a production node client.

Nethermind is an Ethereum execution client written in C# and .NET, and the second most used client on the network. Node operators and infrastructure builders run it to serve JSON-RPC and follow the chain.

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.