Blender - Blender is the open source, cross platform suite of tools for 3D creation.
World Machine - Command powerful tools like erosion and advanced colormaps to create terrain heightmaps, meshes, and textures for your game or 3D scene. Download for Free!
Autodesk 3DS Max - 3ds Max is software for 3D modeling, animation, rendering, and visualization. Create stunning game enrivonments, design visualizations, and virtual reality experiences.
Vue - Create vast expanses of terrains, add trees, select the best point of view and render...
ZBrush - ZBrush is a digital sculpting and painting software solution.
EarthSculptor - EarthSculptor is a realtime terrain height-map editor and paint program featuring an easy to use...