Sanctuary Shattered Sun Map Editor
The very kind folk behind Sanctuary: Shattered Sun have made their map editor available to anyone who wishes to try it.
The software is in it's infancy, so please consider that it won't be the most polished experience at this time. For information on how to use it there are a couple of really good introductory YouTube videos.
Getting Started:
Introduction to Height Maps:
Keep an eye out on the forums for more mapping information. Thousands of people are waiting to wage war across your creations!
Be sure to read the guide for map editors: Map editor guide for mappers