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.
CAD Scripts automates a range of CAD tasks. It includes text_to_dxf for drawing figures in DXF format by specifying co-ordinates in an input text file.It also includes support for automatically create an entire beam and column structure for FreeCAD or StadPro after entering the specifications of a building.
Alliance CAD System is a set of EDA tools and portable cell libraries for VLSI design. It covers a wide range of the standard design flow (from VHDL up to layout). It includes a VHDL simulator, RTL synthesis tools, place and route tools, netlist extractor, DRC, and a layout editor.
CYCAS is a 2D+3D CAD package for drafting and design in high quality and for creating 3D presentations and technical illustrations easily. Some of its features include an easy-to-handle user interface, special architectural elements and functions, a WYSIWYG display, printing, plotting, import and export filters, photorealistic rendering with POV-Ray, documentation and tutorials, example drawings, and an extendable 2D/3D symbols library.
FREEdraft is a 2D mechanical CAD program. You can draw points, sketch geometry, segments and arcs to precise dimensions, and label items with text. You can trim and edit geometry, incorporate colors and linestyles, and then save your drawing. Importation of geometry from DXF files is now supported as well.
VariCAD is a 3D/2D CAD system for mechanical engineering. In addition to standard tools for 3D modeling and 2D drafting, the CAD system provides tools for sheet metal unbending and crash tests, libraries of standard mechanical parts (ANSI, DIN) and symbols, mechanical part calculations, and tools for working with bills of materials (BOMs) and title blocks. VariCAD supports STEP, STL, IGES, DWG, and DXF file formats.
Fandango is a GL-rendered, Python-scripted CAD program. The low-level functionality is programmed in C++, and then the relevant functions are exposed to Python and used as building blocks for more functions. Currently the memory core allows lines, triangles, line strips, and triangle strips. Texture, blending, and lighting can be switched on and off from a command line.