Natural Biomes 2 is a mod that adds more biomes that feel vanilla. On top of that this mod also adds variation to the biomes. For example I have mountain, extreme hills, and normal variants of most biomes.
Extreme Desert Hills
Extreme Grass Hills
Extreme Snow Hills
This mod uses a config file to change biome ids. If another biome mod has the same ids as mine they will cause chunk loading issues and load together. Change the ids in the config file to fix this!
However, to make life easier for you guys I have coded NB2 to work with the following mods