OpenSCAD was created in 2009 and allows users to create their own 3D models. It is definitely more focused for small parts, and not for organic structures or art projects. The versatile program is available for download through Windows, Mac, and Linux. 3D printing service i.materialise is a fan of the software. In fact, it recently posted an "OpenSCAD Tutorial & Cheat Sheet: Getting Started with a Free CAD Software" tutorial in the company blog. Using step-by-step instructions, a cheat sheet, and four helpful videos, you can learn how to use the powerful software, and how to create your first model for 3D printing. Learn more at 3DPrint.com: https://3dprint.com/161219/openscad-...lise-tutorial/