What to do and what to choose - GreatDevelopers/LibreCAD GitHub Wiki

These are CAD Kernels, ( Paid/Non-opensource/opensource/free/Non-Free )
en.wikipedia.org/wiki/Geometric_modeling_kernel

CAD Kernels that can be used,
1. BRL-CAD’s engine
2. https://code.google.com/p/wildcat-cad/
3. Openscad’s engine