LangChain

LangGraph is a free, MIT-licensed Python framework for developers building AI agents that need to keep state and handle complex tasks. It gives teams control over how an agent moves between steps, where people can intervene, and what happens when a long-running task is interrupted.

DSPy is a Python framework for developers building AI applications whose tasks need clear inputs, predictable output types, and measurable results. You define what a language model should produce, then compose those tasks into a larger program. It's open source under the MIT license.

Haystack is a Python framework for developers building self-hosted AI agents, document search, and apps that answer questions using their own data. Its modular pipelines let teams control which information reaches a model and inspect how retrieval, memory, tools, and generation contribute to an answer. It's open source under Apache 2.0.

RubyLLM is an MIT-licensed AI framework for developers building Ruby and Rails applications with local or hosted models. Its shared API lets an application switch between Ollama, cloud providers such as Anthropic and OpenAI, and OpenAI-compatible endpoints without rewriting its model integration. The framework runs in your application; model processing happens at the local or hosted backend you choose.

LangChain4j is an Apache 2.0 open-source Java library for developers building chatbots, assistants and AI agents in JVM applications. It connects application code to local LLM backends such as Ollama as well as cloud providers such as OpenAI and Google Vertex AI. Where model requests go depends on the backend you choose.