See also Elasticsearch and Manticore Search
OpenSearch is a community-driven, Open Source search and analytics suite derived from Apache 2.0 licensed Elasticsearch 7.10.2.
Tiki 21.x, 22.x, 23.x and 24.x is expected to work fine with OpenSearch 1.0 (as they do with Elasticsearch 7.x). However, OpenSearch and Elasticsearch will diverge sooner or later, so it would make sense to add native support for OpenSearch. If you need this, please contact Marc Laporte to discuss.