Frege is a non-strict, pure functional programming language in the spirit of Haskell. It enjoys a strong static type system with type inference. Higher rank types are supported, though type annotations are required for that.
Frege programs are compiled to Java and run in a JVM. Existing Java Classes and Methods can be used seamlessly from Frege.
The Frege programming language is named after and in honor of Gottlob Frege.
There have been attempts to port Haskell to the JVM, though said projects seem failed or stuck. The common wisdom suggests that it is not easily possible.
Frege is thought as a substitute for this missing GHC port. While not derived from any existing Haskell implementation, it is more or less equivalent to Haskell 2010. Please see the wiki page that details the differences.