CrewAI
Python framework for multi-agent AI — define a "crew" of specialized agents with roles, goals, tools. Open source, rapidly growing in 2024.
João Moura created it in 2024. Competitors: AutoGen (Microsoft), LangGraph (LangChain), Swarm (OpenAI experimental). Typical pattern: a "researcher" agent + "writer" agent + "editor" agent collaborate sequentially or hierarchically. Builds on LangChain but has its own agent loop. Strictly agent-focused vs LangChain's general LLM orchestration.