CadQuery is an intuitive, easy-to-use Python based language for building parametric 3D CAD models. This tutorial walks you through a simple model to show some of the core concepts. If you're curious about CadQuery, or are trying to get started, this is a great place to start.
CadQuery FreeCAD Module on GitHub: https://github.com/jmwright/cadquery-freecad-module
FreeCAD website: http://freecadweb.org/
CadQuery Module Documentation: https://github.com/jmwright/cadquery-freecad-module/wiki
CadQuery Documentation: http://parametricparts.com/docs/
CadQuery on GitHub: https://github.com/dcowden/cadquery
