ACFTools is a utility for manipulating X-Plane flight simulator aircraft and weapon models without using its Plane Maker. It can decode both Apple and Intel ACF/WPN formats into plain text files with a syntax similar to C, which can be edited and then re-converted into binary data. It is able to extract almost complete 3D models of aircraft (fuselage, floats, tanks, wings, stabs, propellers, engines) and write it in AC3D modeler format. Edited 3D parts can then be merged into plain text and consequently converted into binary ACF files.
Asymptote is a powerful descriptive 2D and 3D vector graphics language for technical drawing, inspired by MetaPost but with an improved C++-like syntax. It provides for figures the same high-quality level of typesetting that LaTeX does for scientific text. Asymptote is a programming language as opposed to just a graphics program. It can exploit the best features of script (command-driven) and graphical user interface (GUI) methods. High-level graphics commands are implemented in the language itself, allowing them to be easily tailored to specific applications.
BRL-CAD is a powerful constructive solid geometry solid modeling system that includes an interactive geometry editor, ray-tracing support for rendering and geometric analysis, path-tracing for realistic image synthesis, network distributed framebuffer support, and image and signal-processing tools.
CADSM is a basic 3D CAD with advanced motion simulation capabilities. It is suitable for anyone interested in learning 3D CAD and motion simulation inexpensively before using more sophisticated packages. Educators, students, and new engineers will find it ideal for the teaching and learning of geometry, kinematics, dynamics, vibrations, mechanisms, linkages, cams, machine design, and physics. Data can be exported to spreadsheets or the POVRay ray tracer.
Coin is an implementation of Open Inventor. Open Inventor is the de facto standard API for retained-mode 3D graphics programming. Open Inventor has a highly extensible design, and has been designed to allow for rapid development of highly interactive 3D graphics applications in the fields of CAD, engineering, scientific computing, simulation, VRML, and visualization.
FreeCAD is a CAx RAD based on OpenCASCADE, Qt4, and Python. It features some key concepts like Macro recording, Workbenches, and the ability to run as a server. It's also platform-independent. It is is fully scriptable and designed to be easily extensible; only the core functionality is embedded into the core libraries, but all further functionality like support of triangle meshes, CAM, FEM, etc. is implemented in extension modules. Normally, such a module is divided into an 'App' part containing the data structures and algorithms and a 'GUI' containing the graphical representation of data structures, dialogs, workbenches, etc.
Gmsh is an automatic 3D finite element grid generator with built-in CAD and post-processing facilities. Its design goal is to provide a simple meshing tool with parametric input and advanced visualization capabilities. It is built around four modules: geometry, mesh, solver, and post-processing. The specification of any input to these modules is done either interactively using the graphical user interface (based on FLTK and OpenGL) or in ASCII text files using Gmsh's own scripting language.
HeeksCAD is a CAD application. It can import solid models from STEP and IGES files, draw construction geometry and lines and arcs, create new primitive solids, or make solids by extruding a sketch or by making a lofted solid between sketches. Solids can be modified using blending or boolean operations. Models can be saved as IGES, STEP, and STL. The 2D geometry can be plotted with a printer or to HPGL. DXF files can be imported and exported; lines, arcs, spline, ellipses, and polylines are supported. SVG import has similar capabilities. It is possible to make Add-In modules. The HeeksCNC project provides a CAM add-in, and HeeksPython provides a Python console.