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 Professional is the paid version that includes additional advanced drawing tools and supports more file types, most notably AutoCAD dwg and MicroStation dgn files.
With the release of FreeCAD .20 the shortcuts in the Sketcher Workbench changed. FreeCAD is a continually updated project and keybindings can and (unfortunately) do tend to change with each additional release. Thus, this collection of shortcuts may not work in future versions.