Frege (https://github.com/Frege/frege/wiki/_pages) is a language that aspires to “first and foremost become and be advertised as Haskell variant or dialect” per it’s creator ( http://www.infoq.com/news/2015/08/frege-haskell-for-jvm ). Frege is less a unique language and more similar in spirit to JRuby and Jython which are all projects that seek to ‘port’ other language syntaxes to the JVM. But unlike those other languages which are using the benefits of JVM for ‘safety’ and performance reasons…using the JVM with Haskell is quite the opposite. So instead the benefits Frege gets from running on the JVM is the ability to interoperate with Java libraries and run on multiple platforms. This potentially allows Frege to be used in a wider range of programs.
However, I don’t expect a mass exodus from Java. For the foreseeable future, Frege (and even Haskell for that matter) will continue to be a language that is more interesting in academia and to mathematicians and less so for broader Java programming community.