This paper defines a development system for computer-aided design (CAD) algorithms for combinational logic networks. The principle features of this system include graph-oriented commands and control structures, list handling facilities, and an expandable library of commonly used CAD subprograms. Application programs written using the prototype system, CADTOOLS, include worst case path delay analysis, Sandia Controllability and Observability Analysis (SCOAP) testability measure, and logic simulation. The experience with these programs suggests that such a system can reduce the time required to develop CAD programs.