1. A computer-readable storage medium having a data structure stored thereon, the data structure comprising: a first field comprising a key identifying an object; a second field comprising a start version identifier; a third field comprising an end version identifier; and a fourth field comprising a property value of the object; wherein the second and third field define a range of versions of the object identified by the first field having the property value in the fourth field, wherein the property value comprises a piece of data associated with an object other than version data; wherein a plurality of instances of the data structure define properties of the object and record associated versions of the object allowing for recall and generation of the object without requiring a copying of the object; and wherein the data structure maintains property values for multiple versions of the object and wherein the object is not copied when a property value of the object changes.