What you're talking about is UHT milk, which has a shelf life of six to nine months, until opened. And it doesn't need to be kept in the fridge. It's heated to a certain temperature that kills the spores that spoils normal milk.
It is VERY popular in France/Spain/Turkey, because of the heat, but I think it's nasty. Saying that, in other areas it's probably mostly used for little portions of milk you might get at a gas station with your coffee, or on a train/plane, etc...
