OpenSCAD is a free software application for creating solid 3D computer-aided design (CAD) objects. It is a script-only based modeller that uses its own description language; parts can be previewed, but cannot be interactively modified by mouse in the 3D view. An OpenSCAD script specifies geometric primitives (such as spheres, boxes, cylinders, etc.) and defines how they are modified and combined (for instance by intersection, difference, envelope combination and Minkowski sums) to render a 3D model. As such, the program does constructive solid geometry (CSG). OpenSCAD is available for Windows, Linux and macOS.