Haskell is, as of 2001, the functional language on which the most research is being performed. Several variants have been developed: parallelizable versions from MIT and Glasgow, both called Parallel Haskell, more parallel and distributed versions called Goffin and Eden, an eager version called Eager Haskell and several object oriented versions: Haskell++, O'Haskell and Mondrian.
An educational version of Haskell called Gofer was developed by Mark Jones. It was supplanted by HUGS, the Haskell User's Gofer System.
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