The Copyright of the fonts belongs to the The Department of Mathematics of the University of the Aegean, Karlobasi, Samos, Greece If you want to use this font family in commercial work (like in books) you *must* include in the Copyright section the fact that you are using "Kerkis (C) Department of Mathematics, University of the Aegean". The Copyright of the Babel package and it's greek option must still be respected. The Copyright of kerkis.sty belongs to A. Syropoulos and A. Tsolomitis.