I use QGis www.qgis.org. ...

Published July 29, 2015 12:59 by Andres Alcolea Rodriguez, Head of Groundwater Division, TK Consult AG

I use QGis www.qgis.org . Easy to use and the quality of the maps is awesome. If you need an easier one, use Golden Software Surfer 10, but this one is not free. Good luck.