Descriptive geometry consists of procedures originally designed to solve 3-space geometry problems by graphical constructions and measurement instead of by computation. However, in addition to this it unifies and simplifies the approach to many such problems. When one can call subroutines that compute new coordinates that correspond to those obtainable from the graphical constructions, there is the three-way advantage of the approach of descriptive geometry, the accuracy of computation and the speed of the digital computer. DESCRIPTRAN makes it possible to program many problems in 3-space with a few statements; it consists of 15 subroutines analogous to the procedures of descriptive geometry.