QCad

2d computer aided design, computer aided manufacturing (CAM)

Andrew Mustun named qcad on Github, owns the development repository https://github.com/qcad and is the main contributor to the project. The repository contributor page lists 13 contributors in total but none of the other 12 seem to have been as active as Andrew Mustun. https://github.com/qcad/qcad/graphs/contributors

The QCAD Community Edition

The QCAD Community Edition is everything that can be downloaded from our public git repository at github.com/qcad/qcad.

The QCAD Community Edition is distributed under the GPLv3 with exceptions to allow commercial plugins and script extensions.
QCAD Professional

QCAD Professional consists of the QCAD Community Edition with various additional, commercial (proprietary) plugins to provide support for the DWG format, improved support for various DXF format versions, improved support for splines and polyline and various other tools and improvements.