Parametric solid construction apps:

• PLaSM
• ImplicitCAD — has much fewer limitations on precision, compared to OpenSCAD
  • it operates on functions, not triangles
  • in general, it should be good at avoiding non-manifold objects [2]
• based on CGAL
  • OpenSCAD
• based on OpenCascade
  • Parametric Parts > CAD Query
  • CScheme
• SchemeCad
• Generative Modelling Language
• FreeCAD