OpenSCAD is software for creating solid 3D CAD objects.

OpenSCAD is software for creating solid 3D CAD models. It is free software and available for Linux/UNIX, Windows and Mac OS X. Unlike most free software for creating 3D models (such as Blender), it does not focus on the artistic aspects of 3D modeling but instead on the CAD aspects. Thus it might be the application you are looking for when you are planning to create 3D models of machine parts, but pretty sure is not what you are looking for when you are more interested in creating computer-animated movies.

OpenSCAD is not an interactive modeler. Instead, it is something like a 3D-compiler that reads in a script file that describes the object and renders the 3D model from this script file. This gives you (the designer) full control over the modeling process and enables you to quickly change any step in the modeling process or make designs that are defined by configurable parameters.

OpenSCAD provides two main modeling techniques: First there is constructive solid geometry (aka CSG), and second, there is an extrusion of 2D outlines. As data exchanges formats for this 2D outline, Autocad DXF files are used. In addition to 2D paths for extrusion, it is also possible to read design parameters from DXF files. Besides DXF files OpenSCAD can read and create 3D models in the STL and OFF file formats.