LlamaIndex
Data framework for LLM applications — indexing and retrieval
Verdict
Best-in-class for document ingestion, chunking strategies, and advanced retrieval (HyDE, hybrid search). Prefer it over LangChain when the core workflow is RAG-heavy.
Other Frameworks & SDKs
- LangChainProduction
Composable LLM application framework — chains, agents, RAG
- DSPyStable
Stanford framework for programming (not prompting) LMs
- HaystackStable
Deepset open-source NLP framework for production LLM pipelines
- Semantic KernelProduction
Microsoft's enterprise SDK for AI apps (.NET, Python, Java)
- InstructorProduction
Structured outputs from LLMs using Pydantic schemas
- Vercel AI SDKProduction
TypeScript toolkit for building AI-powered web applications