Today, we are pleased to announce the release of Elasticsearch 1.6.0, based on Lucene 4.10.4. This is the latest stable version of Elasticsearch and is packed with awesome new features:
- Faster restarts with synced flushing
 - Shard allocation no longer blocks pending tasks JSON response body filtering
 - Security fix for shared file-system repositories
 - Upgrade API for ancient indices
 - More lenient highlighting for Kibana users
 - mlockall for Windows users
 - Fine-grained script settings
 
You can read more in the blog post: https://www.elastic.co/blog/elasticsearch-1-6-0-released