Abstract: A software tool for computing and displaying differences in at least two object oriented workspaces compared and for reconciling the differences by merging the workspaces has at least one object association graph used as a modeled template for defining the nodes and node paths involved in the difference computation, a data tree structure for displaying element hierarchy symmetrically in each of the compared workspaces, an executable function for merging the separate workspaces to reconcile the found differences, and an interactive user display window for visualizing and directing the process. The tool is characterized in that a user monitors the data structures in each workspace from the display window and executes the difference and merge operations through interaction with the data structure.