This script is a fork of Gcodetools v1.2 written by Nick Drobchenko and is released under the same license (GPL v2).
The gcode generators are not an inkscape extension anymore. They are customized for beeing used in the Mr Beam webinterface (see: github.com/mrbeam/OctoPrint). The produced gcode is customized to suit our needs and so may not be your best choice if you are looking for a general purpose Inkscape to gcode script.
Thanks to Nick Drobchenko (nick@cnc-club.ru) who originally started this project. Released under GPLv2.