Elasticsearch 2.0.0 GA, based on Lucene 5.2.1, introduces numerous enhancements including the integration of Pipeline Aggregations, which simplifies client-side computations and facilitates powerful analytic queries like predictive analytics and anomaly detection. The update merges query and filter functions to optimize performance and introduces configurable store compression for better data management. Security is enhanced by running under the Java Security Manager and ensuring documents are fsynced before indexing. Performance improvements include lower heap usage, faster change propagation, and auto-throttling of merges. Core plugins, such as Shield and Watcher, now offer new features like field-level access control and Slack notifications, while Marvel, a monitoring tool, is free for production use. The Sense editor is made open-source, and an Elasticsearch Migration Plugin assists users transitioning from version 1.x to 2.0.