CrewAI

LangGraph

LangChain · Free

LangGraph is LangChain's stateful agent and multi-agent framework that models agent workflows as directed graphs — enabling complex cycles, human-in-the-loop checkpoints, and persistent state across agent sessions. It has become the go-to framework for enterprise agent applications requiring production-grade reliability, observability, and complex workflow management. LangGraph Cloud offers managed hosting with built-in deployment, scaling, and monitoring.

AutoGPT

Significant Gravitas · Free

AutoGPT was the pioneering autonomous agent project that sparked the 2023 AI agent explosion, demonstrating that LLMs could self-direct toward goals using a loop of thought, action, and memory. With over 170,000 GitHub stars, it remains one of the most starred AI repos ever and introduced concepts like agent memory and tool use that are now standard in the field. Its AutoGPT Platform continues development as both an open-source framework and hosted cloud agent service.

BabyAGI is the lightweight task-driven autonomous agent that inspired a generation of agent developers — using a simple loop of task creation, prioritization, and execution to work toward user-defined goals. Despite its simplicity (the original was 140 lines of Python), it demonstrated that effective goal-directed behavior could emerge from basic LLM loops. The project remains influential as a conceptual reference point, though most production use cases have moved to more mature frameworks.