There was Plan 9 source available, but the early releases were in the AT&T Unix mode and required some payment or academic connection. The early demo disks might not have had source - I don't remember - but if not, there was simply no room on a floppy. The CD releases had full source.

Plan 9 was a research system. It was hoped that maybe one day it would become a commercial success, but that was never the prime motivation. It only "failed" as a product, and there are many contributing factors there, including existing systems that were good enough, a desire for people to have "workstations" and ignore the benefits of a completing window UI on a mainframe (Cray was an exception, earlier), and AT&T lawyers refusing to think realistically about open source (about as polite a way I can express a multiyear fight that never ended, only fizzled into stalemate).

As a research system, Plan 9 was a huge success. We're still talking about its ideas 30+ years on.

-rob

On Tue, Jan 31, 2023 at 8:24 AM Larry McVoy <lm@mcvoy.com> wrote:

On Mon, Jan 30, 2023 at 02:03:32PM -0500, Dan Cross wrote:
> On Mon, Jan 30, 2023 at 11:18 AM Larry McVoy <lm@mcvoy.com> wrote:
> > On Mon, Jan 30, 2023 at 11:09:03AM -0500, Dan Cross wrote:
> > > On Mon, Jan 30, 2023 at 10:45 AM Larry McVoy <lm@mcvoy.com> wrote:
> > > > On Mon, Jan 30, 2023 at 10:35:25AM -0500, Dan Cross wrote:
> > > > > Plan 9 was different, and a lot of people who were familiar with Unix
> > > > > didn't like that, and were not interested in trying out a different
> > > > > way if it meant that they couldn't bring their existing mental models
> > > > > and workflows into the new environment unchanged.
> > > > >
> > > > > At one point it struck me that Plan 9 didn't succeed as a widespread
> > > > > replacement for Unix/Linux because it was bad or incapable, but
> > > > > rather, because people wanted Linux, and not plan9.
> > > >
> > > > Many people make that mistake. New stuff instead of extend old stuff.
> > >
> > > Some would argue that's not a mistake. How else do we innovate if
> > > we're just incrementally polishing what's come before?
> >
> > I didn't say limit yourself to polishing, I said try and not invalidate
> > people's knowledge while innovating.
> >
> > Too many people go down the path of doing things very differently and
> > they rationalize that they have to do it that way to innovate. That's
> > fine but it means it is going to be harder to get people to try your
> > new stuff.
> >
> > The point I'm trying to make is that "different" is a higher barrier,
> > much, much higher, than "extend". People frequently ignore that and
> > that means other people ignore their work.
> >
> > It is what it is, I doubt I'll convice anyone so I'll drop it.
>
> Oh, I don't know. I think it's actually kind of important to see _why_
> people didn't want to look deeper into plan9 (for example). The system
> had a lot to offer, but you had to dig a bit to get into it; a lot of
> folks never got that far. If it was really lack of job control, then
> that's a shame.

It's certainly not just job control. I think it's a combo of being
unfamiliar, no source (at first I believe) and Linux was already
pretty far along.

The lesson is that if there is an installed base, and you want people
to move, you have to make that easy and there has to be a noticeable
gain. Plan 9 sounded cool to me but Linux was easy.
--
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Larry McVoy Retired to fishing http://www.mcvoy.com/lm/boat