Milvus is one of the most mature and feature-rich open-source vector databases available, purpose-built for similarity search and AI applications. Developed by Zilliz, it supports billion-scale vector search with impressive performance, offering multiple index types (IVF, HNSW, DiskANN, and more) to optimize for different use cases. Its architecture separates storage and compute, enabling excellent scalability for production workloads.

Strengths include robust hybrid search capabilities (combining vector and scalar filtering), a well-documented Python SDK, and strong community support. The multi-language SDK support (Python, Java, Go, Node.js) and gRPC/RESTful APIs make integration straightforward. Being fully open-source with an Apache 2.0 license is a major advantage for cost-conscious teams.

Limitations include a steeper learning curve compared to simpler alternatives like Chroma or Pinecone, and operational complexity when self-hosting at scale " though Zilliz Cloud offers a managed option. Resource requirements can be significant for large deployments. Overall, Milvus is an excellent choice for teams needing a production-grade, scalable vector database with full control over their infrastructure.