3d Design Software Websites:
ac3d.org
AC3D - Easy to use 3D software
AC3D - 3D Software - View, Edit and Design great 3D graphics with ease. Free trial downloads for Windows, Mac and Linux. Widely used for Second Life and X-Plane.
3dsim.com
Engineering Simulation & 3D Design Software | Ansys
Ansys engineering simulation and 3D design software delivers product modeling solutions with unmatched scalability and a comprehensive multiphysics foundation.