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