QCAD.org Forum

If you choose to use the free QCAD Community Edition (without the features and tools of QCAD Professional and without DWG support), you can simply remove the trial add-ons from a downloaded and installed QCAD Professional or QCAD/CAM trial version:

Windows:
[QCAD installation folder]\plugins
qcaddarkstyle.dll
qcaddwg.dll
qcadpdf.dll
qcadopengl3d.dll (QCAD/CAM only)
qcadpolygon.dll
qcadproj.dll
qcadproscripts.dll
qcadtriangulation.dll
qcadspatialindexpro.dll
qcadcamscripts.dll (QCAD/CAM only)
Do NOT delete qcaddxf.dll or you won't be able to load or save any files.

macOS:
QCAD.app/Contents/PlugIns (Right-click on QCAD.app and click Show Package Contents)
libqcaddwg.dylib
libqcadopengl3d.dylib (QCAD/CAM only)
libqcadpdf.dylib
libqcadpolygon.dylib
libqcadproj.dylib
libqcadproscripts.dylib
libqcadtriangulation.dylib
libqcadspatialindexpro.dylib
libqcadcamscripts.dylib (QCAD/CAM only)
Do NOT delete libqcaddxf.dylib or you won't be able to load or save any files.

Linux:
[QCAD installation directory]/plugins
libqcaddarkstyle.so
libqcaddwg.so
libqcadpdf.so
libqcadopengl3d.so (QCAD/CAM only)
libqcadpolygon.so
libqcadproj.so
libqcadproscripts.so
libqcadspatialindexpro.so
libqcadtriangulation.so
libqcadcamscripts.so (QCAD/CAM only)
Do NOT delete libqcaddxf.so or you won't be able to load or save any files.