The programmer's solid 3D CAD modeller
A free and open source multiplatform 3D parametric modeler
A python parametric CAD scripting framework based on OCCT
SOLVESPACE is a free (GPLv3) parametric 3d CAD tool.
Surface Explorer 3D plots mathematical surfaces in 3D.
Converts between many 3D data formats
Application for management of CAD files and projects
3D Engine with some extra features based on the D3x3D Engine for VB6