LCS is currently developing a powerful suite of tools for creating and editing heightmap-based terrain systems targetted mainly for the video game sector.
TerreSculptor HMES (HeightMap Editor Software) supports most AAA and indy game engines using industry standard file formats.

TerreSculptor supports heightmap creation and editing, plus importing and exporting of a large number of image, heightmap, digital elevation model, and mesh formats.

TerreSculptor v1.0 is expected to ship in 2013, and will be available in a free non-commercial Standard Edition and a retail Professional Edition.