OpenSCAD?

OpenSCAD doesn't seem to be bad at all, but not thrilled with a custom language to write scripts on it. I found a Rust crate which might help.

I haven't managed yet to write Rust and interoperate with FreeCAD or Blender, so if it is easier to write Rust for OpenSCAD I might settle on OpenSCAD. I have to experiment somewhat to find the most compatible with Rust between the three.