Unix and Multics History
multicians.org
multicians.org
> I said, "I feel proud. It was a privilege to work with Ken Thompson and Dennis Ritchie on Multics, and I am glad to see Unix having the success it deserves." I said more, about the difference in goals of the systems, and about how much easier it was to do things the second time.
> Afterward the local Multicians told me my questioner was one of an anti-Multics faction in Bull. It occurs to me now that he was probably more likely pro-Unix than anti-Multics, but in those days there was a lot of fear and with-us-or-against-us thinking, and Multics was fighting for its life as usual. I don't think my answer satisfied either faction.
> When I finally got a chance to use Unix in 1987, on an Apollo workstation at Tandem, I felt instantly at home. The ls command, control arguments, shell scripts... lots of things felt so similar to Multics that I could go right to work, consulting man pages occasionally to find out what the Unix name of something was.
- long form command names/aliases
- ring security (and perhaps a more secure/isolated container [re]implementation)
- multiple entry points for executables (we sort of have that for busybox, but make it a runtime feature)
- improved memory safety for languages/compilers/runtime (legacy C code could be recompiled with memory checking, possibly with hardware support such as CHERI; stack could grow up rather than down)
- online reconfiguration (of CPUs, memory, devices, etc.) including dynamic splitting of a system (by bringing parts of it offline and then booting them up as a second system)
- smaller kernel (Multics ring 0 was ~628KB; SELinux alone is 2.5x larger[1])