Experience with extensible, portable Fortran extensions

We assess the impact over a three-year period, of the macro-pre-processor MORTRAN, and one of the languages it processes. We confine our assessment to SLAC and Stanford since, although MORTRAN has been widely distributed in the United States and to a lesser extent in Europe, we have no personal knowledge of its impact elsewhere. The impact is attributed to three factors: (1) portability, (2) compatibility (with existing FORTRAN libraries), and (3) extensibility, which is sub-divided into (a) extension of control structures, and (6) extension of data structures. We divide the impact into an "initial" impact which we relate to control structure extensions, and a "secondary" impact which we relate to data structure extensions. MORTRAN is currently being used at SLAC to process large production programs, some of which exceed ten thousand lines of MORTRAN source code.