
Multics Simulator - kristopolous
https://www.multicians.org/simulator.html
======
musicale
I've been running multics on simh for a while - it's amazing and a revelation
to experience some of the ways that it surpasses UNIX (memory safe
implementation in PL/I -> no stack and buffer overflows, unified storage
model, nested ring security and system call architecture, long command forms,
etc.) while also trying out ancient forms of email, emacs, lisp, BASIC, C and
Fortran as well as weird and obsolete, but historically interesting, languages
like BCPL (predecessor of C) and PL/I (predecessor of... nothing, probably,
except maybe Ada in some sense.)

If modern UNIX/Linux distros were to adopt three features from Multics, I'd
love to see memory safe compilation, long-form commands (e.g. in multics, "ls"
is a shortcut for "list-segments"), and ring security (which is basically
flexible nested paravirtualization, enabling many of the things we currently
do with VMs, containers, and user mode drivers.)

------
pjmlp
Also advisable is to spend a couple of minutes going through
[https://www.multicians.org/myths.html](https://www.multicians.org/myths.html)

~~~
yjftsjthsd-h
There's some useful perspective in there, but they're not exactly unbiased.

> Myth: Multics was closed source

> Bull HN has made the entire source available "for any purpose and without
> fee" at MIT as of November 2007.

So it was only proprietary (shared source, looks like) for the first 4
decades. Right.

~~~
sergeykish
I believe UNIX source code was proprietary as well

> Until then, all versions of BSD used proprietary AT&T Unix code, and were
> therefore subject to an AT&T software license. ... This led to Networking
> Release 1 (Net/1), which was made available to non-licensees of AT&T code
> and was freely redistributable under the terms of the BSD license. It was
> released in June 1989. > Within eighteen months, all of the AT&T utilities
> had been replaced, and it was determined that only a few AT&T files remained
> in the kernel. These files were removed, and the result was the June 1991
> release of Networking Release 2 (Net/2), a nearly complete operating system
> that was freely distributable.

Still

> The USL v. BSDi lawsuit was filed in 1992

[https://en.wikipedia.org/wiki/Berkeley_Software_Distribution](https://en.wikipedia.org/wiki/Berkeley_Software_Distribution)

~~~
skissane
We should also consider that the current mainstream definition of "open source
software" only dates from the 1998 founding of the Open Source Initiative; yet
debates about "open"-vs-"closed" source code have been going on in the
industry since at least the early 1980s, and I'm sure someone at some point
would have used the phrase "open source" prior to 1998, but not in the exact
same sense it is currently used.

IBM caused immense controversy in 1983 with their "Object Code Only" (OCO)
announcement–they were no longer going to ship the source code to customers
with new versions of their mainframe operating systems. Might it make sense to
describe that as a shift from "open source" to "closed source"? Even though,
most of that software was copyright by IBM and required paying IBM license
fees to legally use, and hence isn't "open source" by the contemporary meaning
of the phrase.

IBM's "closed source" decision upset a lot of their customers, who found
source code availability very useful in debugging problems and also
implementing local customisations/extensions. And I'm sure competing mainframe
vendors who had an "open source" policy instead (including Honeywell, owner of
Multics) would have emphasised that differential to their customers.

~~~
cryptonector
But open source existed _long_ before 1998.

~~~
skissane
What we now call “open source software” existed before 1998, but _the phrase_
“open source software” wasn’t in widespread use prior to 1998, and any
pre-1998 uses of the phrase don’t have the current quite specific meaning.

The FSF promoted the phrase “free software”. The “open source” term was chosen
as an alternative because (1) English “free” is ambiguous (price vs liberty)
(2) the FSF’s strict ethical stances weren’t very corporate-friendly and so
“open source” avoided the association with FSF which was seen as alienating
many corporate executives (3) it represented a broader range of acceptable
licensing conditions than the FSF’s strict ethics would allow

~~~
cryptonector
There's no need to pick such nits. The point was clear: "open source" -even
with very loose definitions of "open source"\- was one key to Unix's triumph
over Multics. BSD was "open source" even in 1978 because Bill Joy did nothing
to verify that recipients of BSD source had AT&T Unix source licenses.
Eventually BSD became truly open source when the AT&T-Berkeley lawsuit was
settled -- truly open source by the standard you mention, even though that was
before 1998. That no one spoke of "open source" in 1978 is neither here nor
there. Multics is practically unused by comparison to Unix. The End.

~~~
skissane
UNIX was proprietary licensed code developed and owned by AT&T / Bell Labs.
You had to pay for a license. The source was distributed to academic
institutions and OEMs/VARs–but not always the customers of those OEMs/VARs. As
such, in some ways it was less "open source" than Multics was–every Multics
customer got the source, but not all end-users of UNIX (buying it through an
OEM/VAR) did.

The first freely available (without paying for an AT&T license) distribution
of BSD was Net/1 in 1989. (And even that was under a legal cloud which was not
resolved until the USL vs. BSDi lawsuit was settled in 1994.) Active
development and marketing of Multics was terminated in 1987, although bug
fixes continued to be made for existing customers until the last customer site
shut down in 2000. So the statement that "UNIX is open source but Multics is
not" wasn't true in the relevant timeframe, and differences in source model
aren't a good explanation of the failure of Multics vs. UNIX's success.

> BSD was "open source" even in 1978 because Bill Joy did nothing to verify
> that recipients of BSD source had AT&T Unix source licenses.

I haven't heard before the claim that Bill Joy distributed BSD to non-
licensees–which, if true, probably violated the license agreement his employer
signed with AT&T. (Prior to Net/1, BSD lacked a clean separation between code
originally developed by Berkeley, and modified AT&T code). If a person
distributes source code in violation of license agreements, does that make the
source code "open source"?

------
foobarian
I love that one of the main goals of that system was to provide a computing
utility, very similar to what AWS and friends have become.

------
GnarfGnarf
Why?

~~~
pjmlp
To gain an understanding on how it actually looked like, instead of just
listening to UNIX marketing.

~~~
cryptonector
It's not marketing, is it. Unix, then Linux, won all the mindshare. No company
is advertising Unix or Linux as better than Multics. Multics is culturally not
a thing. It wasn't AT&T who dun it. It was Berkeley.

~~~
pjmlp
Free beer has lots of power.

~~~
cryptonector
Doesn't have to be free to get mindshare, though it helps.

Multics lost the mindshare battle when Berkeley started distributing BSD. They
would have had to go open source / free way back then, in 1978 or so.

Mindshare, mindshare, mindshare. That's the key for this sort of thing.

Oracle, for example, locked in SQL mindshare long ago. I'm not sure that Larry
Ellison understands this -- after all, he (well, Safra Katz) killed
OpenSolaris when that was a vehicle for gaining mindshare. But then again,
maybe it was too late for Solaris anyways.

