Yes, thanks I am already using landserf and is a great application that stands out from other similar GIS software for its semplicity and speed, but I had some errors to import shape files.
It would be nice if in the future Terragen would support importing .shp and .dwg and be able to interpolate isolines, I know that this is a GIS issue but I am just frustrated with other slow GIS software(not landserf). I can't wait to stop using them.
Thanks for the advice