Many planning methods are based on mathematical modeling. A multitude of computer aids covers different facets of the planning activity; data management, linear programming, statistical analysis, graphics, and word processing. However, the diversity and complexity of the available software inhibit the widespread use of computers for planning. The integrated Computer-Aided Modeling and Planning (CAMP) system offers a simple and coherent tool for the planner. A Data Definition Language provides the means for building data banks; a Model Definiton Langauge provides the means for defining mathematical models featuring abstract linear programming, advanced array arithmetics, and assertions; a Picture Definition Language facilitates formation of tables and diagrams; a Text Definition Language combines word procssing with illustrations of modeling results. The man-machine interface is based on interactive panels for controlling the planning process and on a command language for analyzing modeling results. A multilingual capability allows selection of the national language for interfacing with the system. The architecture of CAMP is presented, and its design, implementation, and use in regional planning are discussed. © 1989.