Is not a full modpack but the mod is very huge, it is very realistic with thirsty sistems and a food need like vitamins (proteins,dairy,fruits) it all adds to the experience of minecraft, but thats not all, you cant make a pickaxe or even planks, you start only with the habilities of making tools out of rock that you pick from the ground, you have affinity sistems with animals.. you cant shear a sheep or milk a cow in the moment you find, you have levels of habilities like butchering, mining, cooking, etc.. the pregnant animal (after mating, after the process of affinity..) takes time, you have bigger animals to make better breeds, the game is just awesome.. it brings a new world to minecraft, please take my suggestion.
Thanks for the attention, Sorry for any bad english or misspelling (I'm brazillian!)
All the instructions you guys gonna need is here http://terrafirmacraft.com/f/download.html/