FOSS CAD softwares. I know FreeCAD exists but it’s very unintuitive compared to the proprietary ones. I am thankful that it exists but it’s a long way apart to become a household name like Blender.
I wish I could start writing one but I don’t have a clear picture of requirements to plan and start writing one. If anyone is expert in this field please link some research papers and guidelines for someone to start fresh.