L3DT
6.7#6 in game map generators$34.95 one-timeFree planLinuxWindows
Visit
L3DT suits game developers and digital artists building large 3D worlds who need terrain design, editing, and map generation. The free edition may suit smaller maps, while Professional is for larger heightfields and textures.
World Machine suits artists working with digital terrain in game, film, and visualization pipelines. Basic may fit non-commercial projects that can work within its output-size limit.