FreeCAD

FreeCAD is a parametric 3D modeler made primarily to design real-life objects of any size. FreeCAD uses parametric modeling to allows users to easily modify their design by going back into the model history and changing its parameters.

FreeCAD is open-source, highly customizable, scriptable, and extensible. FreeCAD is multiplatform meaning that it can function on Linux, Mac, and Windows. FreeCAD can also read and write many open file formats such as SVG, STL, and many others. FreeCAD is a full GUI application that comes with a 3D viewer that allows fast rendering of 3D scenes and a very accessible scene graph representation.

FreeCAD also runs a command line application with low memory footprint. In the command line mode, FreeCAD runs without its interface, but with all its geometry tools. Through this, FreeCAD can be used as a server to produce content for other applications. Users can import FreeCAD as a python module. This is possible inside other applications that can run Python scripts or in a Python console.

The workbench concept, it enables the FreeCAD interface tools to be grouped by workbenches. Through this, it allows users to display only the tools used to accomplish a certain task to help in keeping the workspace uncluttered and responsive and the application fast to load. The plugin or module framework for late loading of features enables dividing FreeCAD into a core application and modules that are loaded only when needed.

The parametric associative document objects allow all objects in a FreeCAD document to be defined by parameters. The parameters can then be modified on the fly and recomputed anytime.