In the annals of UNIX gaming, have there ever been
notable games that have operated as multiple processes, perhaps using formal IPC or even
just pipes or shared files for communication between separate processes
I don't know any Unix examples, but DTSS (Dartmouth Time Sharing
System) "communication files" were used for the purpose. For a fuller
story see
https://www.cs.dartmouth.edu/~doug/DTSS/commfiles.pdf
This is probably a bit more Plan 9-ish than UNIX-ish
So it was with communication files, which allowed IO system calls to
be handled in userland. Unfortunately, communication files were
complicated and turned out to be an evolutionary dead end. They had
had no ancestral connection to successors like pipes and Plan 9.
Equally unfortunately, 9P, the very foundation of Plan 9, seems to
have met the same fate.
Doug