8. A non-transitory computer-readable storage medium encoded with a computer program comprising instructions that, when executed, operate to cause a computer to perform operations comprising: providing a plurality of items, each item of the plurality of items being uniquely identified by an identifier and comprising at least one core attribute, the at least one core attribute being of a variable data type; defining a first context that describes a first set of items from the plurality of items, and that can describe a first other context, the first context including at least one of a first default context attribute and a first overriding context attribute, the first other context comprising one or more items of the first set of items; defining a second context that describes a second set of items from the plurality of items, and that can describe a second other context, the second context including at least one of a second default context attribute and a second overriding context attribute, the second other context comprising one or more items of the second set of items; generating a description language based on the first and second contexts; evaluating the description language based on the first context; generating a first list as a sub-set of items of the plurality of items based on the first context, wherein the first default context attribute is assigned to at least one item of the first list if the at least one item does not include a corresponding attribute, and wherein the first overriding context attribute replaces a corresponding core attribute of at least one item of the first list if the corresponding core attribute conflicts with the first overriding core attribute, the first list being associated with a first version of a software product; and displaying the first list.
13. The non-transitory computer-readable storage medium of claim 8 , wherein the operations further comprise: defining at least one of the first context and the second context based on a value of a core attribute of each of the items of the plurality of items.