"very old bug free software" MULTICS came pretty close to that. It's commonly thought that UNIX was so-named to ridicule MULTICS. In reality, the people who

"very old bug free software" MULTICS came pretty close to that. It's commonly thought that UNIX was so-named to ridicule MULTICS. In reality, the people who developed UNIX contributed to MULTICS, it's just that they wanted something fun and easy to work on after having worded so hard and so long on MULTICS. It was written in the mid-sixties. The last MULTICS box was decommissioned in Halifax, I think in 2005 or so. Quite a lot of what we regard as new, in today's operating systems, was implemented in MULTICS in the sixties.