The opensearch project was released a while ago as opendistro and was just renamed to opensearch a year ago [1]. As for features, it depends what you're doing,

The opensearch project was released a while ago as opendistro and was just renamed to opensearch a year ago [1]. As for features, it depends what you're doing, but ES upgraded to Lucene 9 6 months ago [2], and they've had document level alerting for at least two years. [1] https://opensearch.org/blog/technical-posts/2021/07/how-to-upgrade-from-opendistro-to-opensearch/ https://opensearch.org/blog/technical-posts/2021/07/how-to-u... [2] https://github.com/elastic/elasticsearch/issues/74057 https://github.com/elastic/elasticsearch/issues/74057