Subject: Re: Research questions WRT SCO's complaint
From: Ian Lance Taylor <>
Date: 08 Mar 2003 18:00:00 -0800

"Karsten M. Self" <> writes:

>   - What x86 Unices have there been?  When did they emerge?  I'm aware
>     of Xenix (which became SCO), Solaris X86, BSDi, FreeBSD, OpenBSD,
>     NetBSD, AIX/86, Dynix, and (for a broad definition of Intel
>     architechtures), QNX.  I'm not clear of timelines.  And any others
>     would be welcomed.

I believe the first free BSD Unix on the 386 was the Jolitz 386BSD
work which never really finished, but did lead into FreeBSD et al.  I
found some e-mail messages archived here:

Xenix was sold by SCO, but SCO Unix was not Xenix.  It did include
some Xenix code, which everybody avoided because it was buggy.

>   - Early GNU/Linux development -- I know Maddog (then with DEC) got
>     involved in 1991/92.  Any other Unix vendor types on the bandwagon
>     early?  Cygnus also had ties to Sun IIRC.

Ted Ts'o was doing Linux stuff pretty early on, at M.I.T. so he had
access to various sorts of systems.  His home page is

>   - Unix marketshare.  Does anyone have values for breakdown of
>     marketshare through the 1990s of the major Unix flavors?  My
>     understanding is that SCO was never much more than a bit player in
>     the x86 market.  Possibly a fair number of deployments, but low
>     overall valuation.

My recollection, on the other hand, is that SCO completely dominated
the x86 Unix market in the 80s and early 90s.  They started with
Xenix, using code spun out of Microsoft.  They moved on to real Unix.
I don't think there was a serious commercial competitor to SCO Unix on
x86 for a long time.  Solaris x86 came much later.  There was another
Unix based on the AT&T code, but I can't remember the details.  I
don't think anybody used it, since SCO was much cheaper.  I think SCO
was mostly displaced by *BSD and Linux.

>   - SCO's primary thrusts appear to be trade secret / contract
>     violation, and possible (though unspecified) copyright violation.
>     Claiming trade secret status on a design and concept which are now
>     33 years old, the basis of an open standard (POSIX) and a brand
>     certification (Unix98), as well as the foundation of an entire
>     industry and family of competing products:  (Sun:  Solaris, HP:
>     HPUX, IBM: AIX, BSDi: BSDi, Data General: DGUX, DEC (now HP): Tru64,
>     SGI: Irix, GNU/Linux, Minix, GNU/Hurd, OpenBSD, FreeBSD, NetBSD...)
>     SCO can hardly claim trade secrecy status based on this
>     preponderence of implementations (many on, or including, an x86
>     port).  Anyone familiar with the early POSIX compliance status of
>     GNU/Linux itself?

POSIX compliance was an early goal of GNU/Linux, and pretty much drove
the design of things like the tty layer (since POSIX defined a largely
new tty/session layer, based only loosely on SVR4).