Bailey presents a new version of a Fortran multiprecision computation system using Fortran 90. Unlike its predecessors, this new approach does not require a translator program. The translation of Fortran code is accomplished by using the advanced features of Fortran 90, such as derived data types and operator extensions. This approach results in more reliable translation and allows users the full power of Fortran 90. Integer, real, and complex multiprecision variables are available with the usual mixed-mode operations and many of the standard library of mathematical functions. A brief final section describes the use of this package to examine a conjectured identity, which is verified to 100 digits precision.

The principal contribution of this paper is to extend the availability of multiprecision computing to Fortran 90 and thus to many high-performance computing environments. The use of more advanced data structures and operator overloading makes such developments more valuable, because it allows essentially standard code to be rerun using higher-precision arithmetic. This package may therefore prove to be a valuable asset in testing and validating mathematical software.