FreeCAD

FreeCAD is a 3D CAD/CAE parametric modeling application. It is primarily made for mechanical design, but also serves all other uses where you need to model 3D objects with precision and control over modeling history.

OpenSCAD

The short description describes the project briefly, it should not be longer than one or two sentences.

TexTuring

Sculptgl

SculptGL is a web sculpting application.

Blender

Blender is the free and open source 3D creation suite. It supports the entirety of the 3D pipeline—modeling, rigging, animation, simulation, rendering, compositing and motion tracking, even video editing and game creation.

Triangle (It is not a freeware, until proved otherwise)

for generated Delaunay triangulations