OpenSCAD - OpenSCAD is a software for creating solid 3D CAD objects.
FreeCAD - An open-source parametric 3D modeler
libfive Studio - A minimalist GUI for solid modeling with the libfive kernel.
ImplicitCAD - ImplicitCAD is a programmatic CAD program, implemented in Haskell.
CadQuery - CadQuery is a parametric cad script framework
BRL-CAD - BRL-CAD: Open Source Solid Modeling