Elasticsearch is a distributed search engine supporting various data types, including vectors, and provides scalable vector search capabilities, making it a popular choice for modern AI-powered applications. It can be extended with the k-NN plugin to provide scalable vector search using HNSW and Lucene, enabling hybrid semantic and keyword search capabilities.

Awesome-Moviate is a movie search and recommendation engine demo that combines BM25 keyword search, semantic vector search, and hybrid search using Weaviate as the underlying vector database, serving as a practical example of hybrid retrieval for media content.

Arroy is an open-source library for efficient similarity search and management of vector embeddings, useful in vector database systems.

Crate is an open-source distributed SQL database with support for vector data types and vector search, suitable for AI-driven applications.

cuVS is an open-source library from RAPIDS for fast, GPU-accelerated vector search, useful for building high-performance vector databases.

Havenask is an open-source distributed search engine with support for vector search, designed for large-scale AI and search applications.