Should also support Clojure as per discussion and request on mailing list http://mail-archives.apache.org/mod_mbox/nifi-dev/201506.mbox/%3CCAMpSqch4GK1gnw6M1u8tH6AN8e_miXZN5SNkAeMjBujXYGqJiw%40mail.gmail.com%3E
UPDATE: The ScriptEngine for Clojure is not being maintained and is not currently available via Maven Central or a public repository. Recommend adding Clojure as a separate Improvement Jira case.
UPDATE: Scala support proved too buggy using plain script engine. Needs much further analysis/review/testing before inclusion.