Source : Free On-Line Dictionary of Computing

FX-87
     
        Effects.  A {polymorphic} language based on {Scheme}, allowing
        {side effects} and {first-class} functions.  It attempts to
        integrate functional and {imperative} programming.
        Expressions have types, side effects (e.g. reading, writing or
        allocating) and regions (stating where the effects may occur).
     
        Versions: FX-89, {FX-90}.
     
        {(ftp://brokaw.lcs.mit.edu/)}.
     
        ["The FX-87 Reference Manual", D.K. Gifford
         et al, MIT/LCS/TR-407, Oct 1987].
     
        (1995-01-31)