Blender is a free 3D animation studio. It includes tools for modeling, sculpting, texturing (painting, node-based shader materials, or UV mapped), UV mapping, rigging and constraints, weight painting, particle systems, simulation (fluids, physics, and soft body dynamics and an external crowd simulator), rendering, node-based compositing, and non linear video editing, as well as an integrated game engine for real-time interactive 3D, and game creation and playback with cross-platform compatibility.
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.
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.
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.
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.
K-3D is a 3D modeling, animation, and rendering system for GNU/Linux & Win32. Features include creation and editing of geometry in multiple realtime OpenGL solid, shaded, and texture-mapped views; unlimited undos and redos; complete extensibility at runtime through third-party plugins; animated procedural geometric effects; all parameters animatable through a consistent control-spline based interface; rendering pipeline to Renderman Interface compliant rendering engines; optimization for use with the Aqsis rendering engine, which features solid modelling, true displacement, and user programmable shaders; and support for background and batch rendering.