QCAD

QCAD is a free, open source application for computer aided drafting (CAD) in two dimensions (2D). With QCAD you can create technical drawings such as plans for buildings, interiors, mechanical parts or schematics and diagrams. QCAD works on Windows, macOS and Linux.

QCAD is a capable 2D DXF based CAD package, QCAD Professional adds additional features. QCAD was the original codebase for LibreCAD

See

• https://en.wikipedia.org/wiki/QCAD