Methods and apparatus for user-directed, efficient comparisons of sets of objects. A user generally selects two sets of objects to be compared. The objects are, in general, hierarchically structured. The user may also specify criteria for selecting a desired subset of objects in the two sets of objects...http://www.google.com.au/patents/US6278452?utm_source=gb-gplus-sharePatent US6278452 - Concise dynamic user interface for comparing hierarchically structured collections of objects
