I'm going to need more history here on exactly what you linked this is insanely interesting. Alternate windows things in unix land are always interesting
Undoubtedly a reference to CMU's Andrew project [1], which was an experimental distributed computing environment from the 1980s - with an emphasis on providing infrastructure for pedagogy.
Ideas developed by Andrew and Project Athena [2] can still be seen in contemporary software today: window managers, distributed file systems and authentication, compouns documents , etc.
of note AndrewFS (think cousin of NFS).. with features pertaining to systems being "offline" and "online" alternately, but still accessing the same global file / directory namespace, still reading and writing, so some type of git or cvs style merging also exists in that filesystem
