Blender is a free and open source 3D animation suite. It supports the entirety of the 3D pipeline—modeling, rigging, animation, simulation, rendering, compositing and motion tracking, even video editing and game creation. Advanced users employ Blender’s API for Python scripting to customize the application and write specialized tools.
ZCAD is simple CAD program for technical drawings and electrical wirings and devices. It supports the DXF2000, DWG, PDF/PS/SVG/EPS and ZCP file formats and SHX or TTF fonts, is cross-platform, uses fast OpenGL rendering, allows polar tracking and taking object snapshots.