MPFUN: A Multiple Precision Floating Point Computation Package
    David H. Bailey   (dbailey@nas.nasa.gov)

    Package of Fortran subroutines to perform multiprecision
    floating point arithmetic.  Also includes a program that
    can automatically convert ordinary Fortran-77 code into code
    that calls the MPFUN routines.  
    Keith Briggs says: "It's a masterpiece, and the state of the art 
    as far as Fortran goes."
    Documentation in TeX format.  Unrestricted distribution
    allowed at no cost.