EElasticsearchElastic N.V. · Vector databasesIn-depth entryDistributed search and analytics engine on Apache Lucene with full-text, aggregations, vector search and ES|QL; triple-licensed AGPL, SSPL and Elastic LicenseAGPL-3.0-only OR SSPL-1.0 OR Elastic-2.0Open sourceFreeSelf-hostedNov 2, 2026
PpgvectorAndrew Kane (pgvector project) · Vector databasesIn-depth entryPostgreSQL extension adding vector types, distance operators and HNSW/IVFFlat indexes for similarity search inside the databasePostgreSQLOpen sourceFreeSelf-hostedNov 2, 2026
QQdrantQdrant Solutions GmbH · Vector databasesIn-depth entryOpen-source vector search engine written in Rust with filterable HNSW indexes, sparse and multi-vector support, REST/gRPC APIs and a managed cloudApache-2.0Open sourceFreemiumLocalSelf-hostedNov 2, 2026