Hershey Text extension for Inkscape, as copied from https://github.com/evil-mad/EggBot/tree/master/inkscape_driver
Tutorial: http://www.evilmadscientist.com/2011/hershey-text-an-inkscape-extension-for-engraving-fonts/
Update steps:
git describe --long --dirty --tagscp upstream/hershey* .