Acropora!

3D-Coat is a commercial digital sculpting program from Pilgway designed to create free-form organic and hard surfaced 3D models from scratch, with tools which enable users to sculpt, add polygonal topology (automatically or manually), create UV maps (automatically or manually), texture the resulting models with natural painting tools, and render static images or animated "turntable" movies.

Terragen is a scenery generator, created with the goal of generating photorealistic landscape images and animations.It is already capable of near-photorealistic results for professional landscape visualisation, special effects, art and recreation. Terragen has been used in a variety of commercial applications including film, television and music videos, games and multimedia, books, magazines and print advertisements.

meshmixer is an experimental 3D modeling tool for making 3D mashups without too much hassle.

World Machine is a proven terrain generation solution for artists, game developers, visual effects studios and other visualization professionals

ShapeShop is a new 3D modeling and design tool with a fun, easy-to-learn interface. Sketch-based shape creation and editing tools make it simple to quickly translate your ideas into a 3D shape, and drag-and-drop decal compositing makes texturing simple. Best of all, ShapeShop is free!

Bryce is an award winning, fun, feature-packed 3D modeling and animation package designed to allow new users to quickly create and render stunning 3D environments. Bryce combines exceptional power with an innovative interface for incredible ease of use. Add wildlife, people, props and more to your scenes via the DAZ|Studio character plug-in in addition to terrain, water, sky, rocks, clouds, fog, vegetation, and architecture for which Bryce has long been the standard.

Nem's Mega 3D Terrain Generator is a relatively new terrain generator that takes a step in a completely different direction. Unlike traditional generators where the user must depend solely on the generators generation abilities, this generator gives its users complete 3D control over what their terrain looks like. Users start off with a flat piece of landscape, then add to it with one, or a combination of many powerful generation options. They then have several tools at their disposal to literally grab the terrain and pull it as they want it. It can be saved as .tgm, .map, .t3d, .rmf, or .vmf »

PLOPP is a creative painting tool for cartoon-like 3D scenes without the effort that comes with professional 3D modelling programs. You can build 3D objects very easily! Just paint them in a 2D environment and PLOPP will transform them into 3D! The 3D objects can then be moved or rotated in order to arrange them in a true 3D scene. You can paint different backgrounds and adjust the lighting in the scene. The scenes can be printed, set as the desktop wallpaper, or sent as an ecard.

Geomorph is a height field generator and editor for the Linux operating system.

EarthSculptor is a realtime terrain height-map editor and paint program featuring an easy to use interface designedexclusively for rapid development of 3D landscapes for visualization, multimedia and game development.

PnP TerrainCreator is a highly integrated tool for large scale terrain creation. Featuring manual as well as automated/randomized terrain generation including heightmaps, texturing, vegetation, seas and rivers, static objects and environmental sounds enabeling you to build a complete diversified terrain with just one tool.

Visual Nature Studio 3's redesigned interface makes creating complex scenes easier than ever before! Additionally, faster rendering of animations along with still shots guarantees faster delivery of final product.

DreamScape is sophisticated set of 3DS MAX plug-ins for creating and rendering realistic landscapes, seascapes, skies, clouds, outdoor lighting and more. In contrast to other terrain creation tools for 3DS MAX, DreamScape Terra uses new rendering technologies that occupy much less of your computers memory (RAM) making it possible to render large detailed terrains on even a modest system. An intuitive and friendly user interface will allow you to easily tweak terrain properties, interactively paint elevation, and even to apply erosion effects. We have created an API for those who would like to create custom filters for terrain processing and modification. DreamScape's Terra also allows importing standard DEM, SDTS and Terragen files. The possibilities are unlimited. »