Dune 3D is a work-in-progress parametric 3D CAD application that supports:

• Sketch and constrain in 2D and 3D
• Add chamfers and fillets
• Import STEP models for referencing them
• Export high-quality STEP and STL files

It's the result of gluing together the UI from Horizon EDA with the solver from solvespace and Open CASCADE for a geometry kernel.