OpenSCAD - OpenSCAD is a software for creating solid 3D CAD objects.
CADMAPPER - Instant CAD files for any location on earth
libfive Studio - A minimalist GUI for solid modeling with the libfive kernel.
DWGFREE - DWGFREE is an online platform that comes with a comprehensive collection of CAD blocks that can be downloaded without the need for registration.
ImplicitCAD - ImplicitCAD is a programmatic CAD program, implemented in Haskell.
MAPACAD - MAPACAD is an online website that is providing leverage to designers and architectures to have the ability to download CAD map cities that can be directly used in their projects.