alternatives to
Autodesk's CAD software for 2D drafting and 3D modelling, built around the DWG format. A closed product from Autodesk.
2 alternatives
LibreCAD is a cross-platform 2D CAD program. It can read DXF/DWG, and write DXF/DWG/PDF/SVG files. It supports point/line/circle/ellipse/parabola/hyperbola/spline primitives. The GUI is highly customizable, and has dozens of translations.
2D drafting that reads DXF and DWG and writes DXF, without 3D or AutoLISP.
QCAD - The Open Source 2D CAD. QCAD is a cross-platform CAD solution for Windows, macOS and Linux. It supports the DXF format and optionally the DWG format (through a proprietary plugin).
2D drafting on DXF; DWG support comes with a proprietary plugin in QCAD Professional.