> They have open sourced it (https://github.com/elastic/elasticsearch/tree/master/x-pack/... https://github.com/elastic/elasticsearch/tree/master/x-pack/...), b

> They have open sourced it (https://github.com/elastic/elasticsearch/tree/master/x-pack/... https://github.com/elastic/elasticsearch/tree/master/x-pack/...), but you cannot (legally) use it without a paid subscription That's called Source-available and sometimes that's even worse because you (legally) cannot re-implement something similar after you have looked at the code.