Some properties of APL programs

Some results of a study of the static usage of features of the APL language is presented. We compare several characterizations of APL programs with previously measured FORTRAN data, and discuss the significant differences observed. The verity of popular rumors and intuitions about APL programs is also examined. APL users appear to take advantage of the unique matrix features inherent in APL, but in general, use extremely heavily only a small fraction of the available features. The distribution of use agrees well with the so-called "80-20 rule".