OpenSCAD is software for creating solid 3D CAD objects.
It is free software and is available for Linux/UNIX, MS Windows and Mac OS X.
While not the easiest program to understand out-of-the-box, OpenSCAD is our webmaster’s preferred program for creating .stl files.
With a simple to use “programming” language and extensive examples, OpenSCAD allows to to create items, tweak their design, and know that the final product will be printable.
The software is free and wildly used in the 3D Printing community.