The above graph represents a Retrospective History, showing systems that influenced the Xerox Star (8010) and those that were influenced by it. Time progresses downwards. Double arrows indicate direct successors (i.e., follow-on versions). Many "influence arrows" are due to key designers changing jobs or applying concepts from their graduate research to products. A modified Bushy tree, co-authored by John Redant and Bruce Dahmer used this original tree as a model.