Weaviate is a Dutch open-source vector database company founded 2019, one of the main open-source alternatives to Pinecone (others are Qdrant and Milvus). Differentiators: (1) Built-in vectorization — no need to call OpenAI embeddings before inserting vectors; Weaviate accepts raw text and auto-converts via configured model (OpenAI, Cohere, HuggingFace, etc.); (2) Native hybrid search — simultaneously uses BM25 keyword search and vector search with fused ranking (production RAG often outperforms pure vector with hybrid); (3) GraphQL interface for elegant complex queries (combining metadata filter + vector + keyword). Production scenarios are mainly self-host (Docker + cluster); cloud version Weaviate Cloud suits mid-size companies wanting open-source DB without ops.