CClickHouseClickHouse, Inc. · Analytical engines & OLAPIn-depth entryOpen-source columnar OLAP database server for fast aggregations over billions of rows, with MergeTree storage, SQL and a managed ClickHouse CloudApache-2.0Open sourceFreeLocalSelf-hostedNov 2, 2026
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
GGrafanaGrafana Labs · Monitoring & observabilityIn-depth entryDashboarding and alerting platform that visualizes metrics, logs and traces from Prometheus, SQL databases and dozens of other data sourcesAGPL-3.0-onlyOpen sourceFreemiumSelf-hostedNov 2, 2026