Adding a fourth forces you to stop repeating consensus and start evaluating. Here is the four-way split. No trophies. - LangGraph: control pick, graph workflows, explicit state. Best when you must see and steer. Worst when you want to move fast. - CrewAI: team pick, role-based agents. Best for a multi-agent demo this week. Worst for exotic control flow. - AutoGen: veteran pick, conversational patterns, deep history. Best when the problem maps to agents talking. - OpenAgents: the wild card. Run it through the same filter: maintenance, contributors, license, pluggable model layer. Fame is not a technical argument. Apply the filter evenly and the data settles the debate faster than any opinion piece. Want the agent without the homework? PrivateLLM deploy sets up your private LLM on AWS for $50 plus usage.