Storm ditches Clojure in favor of Java in its core

Apache Storm 2.0.0 includes significant improvements in terms of performance, new features, and integration with external systems. The new Java-based implementation has improved performance significantly, and made Storm’s internal APIs more maintainable and extensible. Topology jars should depend on the following artifact as of Storm 2.0.0:

Projects using for testing will additionally need to depend on the Storm server jar:

Keep an eye on the Apache Storm blog for additional posts by Storm contributors for more in-depth discussions of new features in Storm 2.0.0 including:

Special thanks are due to all those who have contributed to Apache Storm — whether through direct code contributions, documentation, bug reports, or helping other users on the mailing lists.

Source: storm.apache.org