Yes, but it doesn't have cross links as far as I know. What I have in mind is effectively one more entry in the root. Call it "union" perhaps. In a leaf of that tree, say /union/usr/src/cmd/find, will ne a page that links to all the "find sources in the other systems. I don't know the range of topologies in the Unix Tree. For example, some systems may have /src while others have /usr/src. That could be hidden completely by simply not revealing the path names. Alternatively every level in the union tree could record its cousins in the various systems, as well as its children in the union system. Doug