DSPy is an open-source Python framework from the Stanford NLP group that lets you program LLM applications instead of hand-crafting prompts. Tasks are described through declarative signatures and modules; optimizers automatically derive effective prompts and examples.
Flowise is an open-source low-code tool for building LLM applications and AI agents visually via drag-and-drop. It is built on the LangChain ecosystem and connects models, data sources and tools as nodes.
Haystack is an open-source AI orchestration framework from deepset for building production-ready LLM applications. Modular components — retrievers, generators, routers, tools — are assembled into explicit pipelines for RAG, agents and semantic search.