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.
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.
Ayam is a free 3D modelling environment for the RenderMan interface. It features good RIB export, CSG (all RenderMan primitives supported), and NURBS modelling. Features instancing, arbitrary number of modeling views, object clipboard, independent property clipboard, n-level undo, console, and Tree-View with Drag-and-Drop support.
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.