Amazon: Not OK – Why we had to change Elastic licensing
SSPL is NOT an open source license. 
OSI (Open Source Initiative) released a statement to clarify that, and also respondED to Elastic's claims. 
https://opensource.org/node/1099The community has invested in Elasticsearch and in Kibana, and we need to keep it open source. really open source.Check out this initiative: 
https://logz.io/blog/open-source-elasticsearch-doubling-down...(disclaimer: I'm a developer advocate at Logz.io)
If you also want to take part, email open-es-k@logz.io (or reach out to me @horovits)Let’s keep Elasticsearch and Kibana open source!