LlamaIndex

LlamaIndex is the leading data framework for building retrieval-augmented generation (RAG) and LLM-powered applications. It specializes in connecting LLMs to your private data—documents, databases, APIs—and making that data queryable. The framework handles data ingestion from 160+ sources via LlamaHub, intelligent chunking, embedding generation, and vector indexing. Query engines synthesize answers grounded in your actual data. In 2025, LlamaParse V2 offers superior document parsing with vision model support, and LlamaAgents enables one-click deployment of document processing agents. Perfect for enterprise knowledge bases, document Q&A systems, and semantic search. Often used alongside LangChain—LlamaIndex for data, LangChain for orchestration. Open-source core with LlamaCloud managed services.