APTOS is an open source Apt translator project. It consists of several CAM applications, based on the Apt programming language. It is used to create control programs for cnc mills, lathes, water jets, lasers, and other industrial equipment.
GeekCAD is a free open source CAD system. It's based on Qt4.
Features of this project:
1. dxf import, export;
2. raster bitmaps export;
3. native postscript or pdf export (in future);
4. Python scripting;
5. Parametric drawings.