can be imported as a Python module FreeCAD can be imported into any application that can run Python scripts. As in command line mode, the interface part of FreeCAD is unavailable, but all geometry tools are accessible.
workbench concept. In the FreeCAD interface, tools are grouped by workbenches. This allows you to display only the tools used to accomplish a certain task, keeping the workspace uncluttered and responsive, and allowing the application to load rapidly.
plugin/module framework for late loading of features/data-types. FreeCAD is divided into a core application with modules that are loaded only when needed. Almost all tools and geometry types are stored in modules. Modules behave like plugins; in addition to delayed loading, individual modules can be added to or removed from an existing installation of FreeCAD.
parametric associative document objects. All objects in a FreeCAD document can be defined by parameters. Those parameters can be modified and recomputed at any time. Since object relationships are maintained, the modification of one object will automatically propagate to any dependent objects.
parametric primitive creation. Primitive objects such as box, sphere, cylinder, etc. can be created by specifying their geometry constraints.
graphical modification operations. FreeCAD can perform translation, rotation, scaling, mirroring, offset (either trivial or as described in Jung/Shin/Choi) or shape conversion, in any plane of the 3D space.
constructive solid geometry (boolean operations). FreeCAD can do constructive solid geometry operations (union, difference, intersect).
graphical creation of planar geometry. Lines, wires, rectangles, b-splines, and circular or elliptic arcs can be created graphically in any plane of the 3D space.
modeling with straight or revolvedextrusions, sections and fillets.
topological components like vertices, edges, wires and planes.
testing and repairing. FreeCAD has tools for testing meshes (solid test, non-two-manifolds test, self-intersection test) and for repairing meshes (hole filling, uniform orientation).
annotations. FreeCAD can insert annotations for text or dimensions.
Undo/Redo framework. Everything in FreeCAD is undo/redoable, with user access to the undo stack. Multiple steps can be undone at one time.
transaction oriented. The undo/redo stack stores document transactions, not single actions, allowing each tool to define exactly what must be undone or redone.
built-in scripting framework. FreeCAD features a built-in Python interpreter, with an API that covers almost any part of the application, the interface, the geometry and the representation of this geometry in the 3D viewer. The interpreter can run complex scripts as well as single commands; entire modules can be programmed completely in Python.
built-in Python console. The Python interpreter includes a console with syntax highlighting, autocomplete and a class browser. Python commands can be issued directly in FreeCAD and immediately return results, permitting script writers to test functionality on the fly, explore the contents of FreeCAD's modules and easily learn about FreeCAD internals.
mirrors user interaction. Everything the user does in the FreeCAD interface executes Python code, which can be printed on the console and recorded in macros.
full macro recording and editing capabilities. The Python commands issued when the user manipulates the interface can be recorded, edited if needed, and saved to be reproduced later.
compound (ZIP based) document save format. FreeCAD documents are saved with a .fcstd extension. The document can contain many different types of information such as geometry, scripts or thumbnail icons. The .fcstd file is itself a zip container; a saved FreeCAD file has already been compressed.
fully customizable/scriptable Graphical User Interface. The Qt-based interface of FreeCAD is entirely accessible via the Python interpreter. Aside from simple functions FreeCAD itself provides to workbenches, the entire Qt framework is accessible. The user may perform any operation on the GUI such as creating, adding, docking, modifying or removing widgets and toolbars.
thumbnailer. (currently only Linux systems) FreeCAD document icons show the contents of the file in most file manager applications such as Gnome's Nautilus.
modular MSI installer. FreeCAD's installer allows flexible installations on Windows systems. Packages for Ubuntu systems are also maintained.
In development
An Assembly module that allows one to work with multiple projects, multiple shapes, multiple documents, multiple files, multiple relationships... This module is currently in the planning state.