Not sure what you mean?
All of the previews of the current terrain system were done on the NDISLES map. This was also the only map available in Beta. HTC did the terrain overhaul in house. Players can in turn use the changes HTC made in the Terrain system to make maps. That said HTC made a lot of the maps (like NDISLES). You can see who makes every individual terrain used on HTC's servers under the terrain downloads tab on the website.
Hope that answers your question.