Elasticsearch was open source under the permissive
Apache 2.0 license from its early releases until version 7.10.
In January 2021, starting with version 7.11, Elastic relicensed Elasticsearch under the SSPL and the Elastic License v2, which are not OSI-approved open source licenses. This led Amazon and the community to create
OpenSearch, an open source fork of Elasticsearch 7.10 licensed under Apache 2.0.
In August 2024, with version
8.16, Elastic added the GNU AGPLv3 open source license, making Elasticsearch open source again.
Source:
Elasticsearch is open source, again.