FreeCAD is based on OpenCasCade, a powerful geometry kernel, features an Open Inventor-compliant 3D scene representation model provided by the Coin 3D library, and a broad python API. The interface is built with Qt. FreeCAD runs exactly the same way on Windows, Mac OSX and Linux platforms.
· A complete OpenCasCade-based geometry kernel allowing complex 3D operations on complex shape types, and supports natively concepts like brep, nurbs, booleans operations or fillets
· A modular architecture that allow plugins (modules) to add functionality to the core application. Those extensions can be as complex as whole new applications or as simple as python scripts or self-recorded macros
· A full parametric model allowing any type of parameter-driven custom objects, that can even be fully programmed in python
· Complete access from python built-in interpreter, macros or external scripts to almost any part of FreeCAD, being geometry creation and transformation, the 2D or 3D representation of that geometry (scenegraph) or even the FreeCAD interface
· Import/export to standard formats such as STEP, IGES, OBJ, DXF, SVG, U3D or STL.