There is a registered version of Terragen which allow the user to render in unlimited resolution, other than that it is all the same. There are also quite a fes plugins that works with Terragen, namely "Waterworks" with which breaking water edges, level depth, there is also "Forester" which can created distance scattered populated vegetation..and also "Export Only" which allow terrain in Terragen to export LW, obj, 3ds and some others. The creator, Matt Fairclough of Planetsite is actually on contract work with Doc Mojo (I think) and that is why Terragen at the moment is temporary halted at version 0.884. From what I understand from their user list, Terragen user are expectating a version 1 release someday when Matt finished his contract. This program has all my respect and under expert hands, most image created with it, I find it hard to get by with Vue.