Stilly, in German, that is called Rumtopf, and in French it is a type of macédoine. I don't know of an English name for it.

The fruit is fresh, and the jar should be kept in a dark, cool place (i.e., not on the kitchen counter).

The idea is to add each kind of fruit as it comes into season, starting with strawberries and finishing with plums. It works best with berries and small drupes (apricots, plums), and each layer has to be topped up with both sugar and liquor -- traditionally, rum. If you do it right, it does not -- repeat, not -- ferment; it macerates. It comes out at Christmas, when the fruit-lquor mixture is ladled over ice cream, custard desserts (including bread pudding), rice pudding or plain cake.