|3ds Max 6|
Heck, you don't even need max to use this. With the included instructions and maps, you can EASILY make this in another program using the displacement, diffuse, and sky image files.
The terrain is realistic - snow accumulates more on flatter ground, so the flatter regions are snowy colored, and the steep slopes are rock.
UPDATE: I have a better texture uploaded. Use the bottom one instead of the one that comes in the zip file.