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'The SCO Group cannot expect to win any case based upon application interfaces which it's AT&T, USL and Novell predecessors relased in open standards specifically for the purpose of interoperability.

signal.h, errorno.h,and ioctl are all parts of many released standards including The Open Group and IEEE POSIX Base Specifications and the Federal Information Processing Standards Publication 151-2.

Note that The SCO Group does not own the copyrights on any of those standards and it does not own clear title to the copyrights on most of the AT&T Unix base.

From 1989, the then SCO activity pushed for the adoption of the iBCS Intel Binary Compatibility Specifications across *all* i386 Unix vendors

For the benefit of the entire user base, as well as the industry as awhole, SCO encourages all UNIX System vendors for Intel processors to join SCO, USL, Intel, ISC and OSF in supporting the iBCS-2 standard for x86 applications.

Even SCO admits, no requries these definitions to be present in order to be standards compliant.

'The SCO Group cannot expect to win any case based upon application interfaces which it's AT&T, USL and Novell predecessors relased in open standards specifically for the purpose of interoperability.

signal.h, errorno.h,and ioctl are all parts of many released standards including The Open Group and IEEE POSIX Base Specifications and the Federal Information Processing Standards Publication 151-2.

Note that The SCO Group does not own the copyrights on any of those standards and it does not own clear title to the copyrights on most of the AT&T Unix base.

From 1989, the then SCO activity pushed for the adoption of the iBCS Intel Binary Compatibility Specifications across *all* i386 Unix vendors

For the benefit of the entire user base, as well as the industry as awhole, SCO encourages all UNIX System vendors for Intel processors to join SCO, USL, Intel, ISC and OSF in supporting the iBCS-2 standard for x86 applications.

Even SCO admits, no requries these definitions to be present in order to be standards compliant.

Linux header:
#define EPERM 1 /* Operation not permitted */
#define ENOENT 2 /* No such file or directory */
#define ESRCH 3 /* No such process */
#define EINTR 4 /* Interrupted system call */
#define EIO 5 /* I/O error */
#define ENXIO 6 /* No such device or address */
#define E2BIG 7 /* Arg list too long */

And the POSIX standard says:
The [errno.h] header shall provide a declaration for errno and give positive values for the following symbolic constants. Their values shall be unique except as noted below.
[EPERM]
Operation not permitted.
[ENOENT]
No such file or directory.
[ESRCH]
No such process.
[EINTR]
Interrupted function.
[EIO]
I/O error.
[ENXIO]
No such device or address.
[E2BIG]
Argument list too long.

Conclusion:
This is hogwash. Complete and utter hogwash. Even the descriptions are specified in the standard. You see some minor differences (Argument vs Arg, function vs system call) but it is simply trivial. If this is the "infringing" stuff, the replacement with completely non-infringing comments would be ready in about 30 seconds directly from the standard. I can volunteer to do a cleanroom implementation without neither SCO nor BSD code :p.

Kjella

The parent link is not correct. But This is

Your url has an extra space in it. Run the base defs into one word and it'll work.

http://www.opengroup.org/onlinepubs/007904975/base defs/errno.h.html#tag_13_10

Linux Weekly News has a copy of the letter. The 65 files don't sound quite as threatening when you discover the first 17 of them are errno.h. Quick, someone go warn the IEEE!

>
>Non-Unix Operating system?
>

Ummmm ....

Not according to the Open Group which owns the trademark.

--AC

The first major obstacle for open source applications to gain ground in the enterprise is that many are much more difficult to use than the typical off the shelf product. Open source applications often include greater flexibility and interoperability between systems, but this comes at the price of more complicated setup and configurations needs.

The lack of clear points of contact for conducting business with companies in the "open source" software industry has hampered the ability of that industry to grow effectively within the government, a former Pentagon official said on Thursday.

Cray did this stuff before there were any "C-native" standards for handling 64 bits. I believe they used _int32 for 32-bit ints.

There's a nice Open Group white paper on the subject of different 64-bit programming models written back when the main Unix vendors were making these decisions.

--LP

Oops. I've been corrected... Win31 was LP32. I found a page that talks about all of this stuff.

My definition of Unix comes from here.

Meanwhile, while linux tries to infilitrate the government, the DoD is tyrying to infilitrate the linux. The DoD Defense Information Infrastructure Common Operating Environment is/was an initiative to to define a common software stack to run across multiple platforms that includes software installation, user management, and printing tools. When you talked about putting Linux on the DoD desktop, that used to mean having a DII COE stack for linux. This year DISA released a beta Linux COE kernel and then released the source code for it which can get from anonymous CVS. DISA has paired up with the OpenGroup to define a testable/brandable definition of COE. And there is a project to develop a platform independent COE stack from scratch.

Relevent URLs:

http://www.disa.mil/coe/kpc/linuxpc.html

http://gforge.freestandards.org/projects/qp-coe

http://www.opengroup.org/openbrand/coe

http://opencoe.sourceforge.net

Here are your server software licenses, thank you very much. You can even get a license plate.

ok, opteron is cheaper than sparc (not as good, mind)... but, what do you mean by Solaris is cheaper than UNIX? surely Solaris IS one of the few registered true UNIX operating systems: a feat that GNU/Linux is not aiming towards. i'm not sure if the *BSDs are exluded for not hitting the standards compliance, or if they just didnt want to fork out the cash to "sit the exam".

The Open Group may have to step in to defend the UNIX trademark as the pice at groklaw points out that they are claiming that Linux is an unauthorized workalike to UNIX(TM) however SCO has no standing to make that cliam since it is the open group who controls weather or not an OS is a UNIX(TM).
Now the open group has already stated that the UNIX trademark belongs to them and that they are neutral in matter of SCO v IBM. They have no flavor of Linux certified as a UNIX, so SCO can not arbitrarily assign the UNIX trademark. It sounds to me like the Open Group may have to step in and defend its trademark in court, as if SCO didn't already have to beat up an 800lb gorilla with a spoon.

The Open Group may have to step in to defend the UNIX trademark as the pice at groklaw points out that they are claiming that Linux is an unauthorized workalike to UNIX(TM) however SCO has no standing to make that cliam since it is the open group who controls weather or not an OS is a UNIX(TM).
Now the open group has already stated that the UNIX trademark belongs to them and that they are neutral in matter of SCO v IBM. They have no flavor of Linux certified as a UNIX, so SCO can not arbitrarily assign the UNIX trademark. It sounds to me like the Open Group may have to step in and defend its trademark in court, as if SCO didn't already have to beat up an 800lb gorilla with a spoon.

The Open Group may have to step in to defend the UNIX trademark as the pice at groklaw points out that they are claiming that Linux is an unauthorized workalike to UNIX(TM) however SCO has no standing to make that cliam since it is the open group who controls weather or not an OS is a UNIX(TM).
Now the open group has already stated that the UNIX trademark belongs to them and that they are neutral in matter of SCO v IBM. They have no flavor of Linux certified as a UNIX, so SCO can not arbitrarily assign the UNIX trademark. It sounds to me like the Open Group may have to step in and defend its trademark in court, as if SCO didn't already have to beat up an 800lb gorilla with a spoon.

Allow me to introduce you to certified Unix(R) products. Since you probably aren't familiar with them, branded Unix(R) products meet a strict set of standards to ensure compatibility. Linux might some day qualify to be Unix(R), but not today. Until then it is just a "unix-like" operating system. If Linux ever becomes a certified Unix(R) operating system, it will look like the other certified Unix(R) operating systems. That means one of two things: either pack for bags for the "80s", as you refer to the standard, or the Unix(R) standard breaks with existing interfaces and functionality. Which do you think will happen? Personally I'm not betting on there being a whole gnu standard, nudge nudge.

I just hope Caldera-sco goes after him for misuse of their trademark.
UNIX is a trademark of the open group, not Caldera

You are a liar, a fraud, and a thief.

You are a liar (if in nothing else) in deliberately misquoting Bruce Perens' analysis of the memory allocation routines which SGI contributed to Linux. Bruce Perens clearly did not say (as you claim he did) that we had allowed '...Unix System V code that "didn't belong in Linux" to end up in the Linux kernel' (my emphasis). He nowhere agreed that this was System V code.

You are a fraud in that you you claim that these routines are your company's property. They are not property, and they are not yours. They aren't yours, they weren't SGI's, they weren't AT&T's. You cannot inherit from others that which they do not own.

Algorithms for allocating memory have been developed over a period of over half a century by software developers studying and improving on one another's code. No implementation of these algorithms exists in isolation; none is fresh hewn from virgin intellectual territory. Improvements are incremental and have largely developed in an open and collegiate environment. Linux may, indeed, have learned some things from UNIX[tm]; but UNIX in its turn got the algorithms from MULTICS, TRIPOS, CPL and others lost even further in the mists of time. You cannot simply stop this process at an arbitrary point and say 'now this is property'. It is not property, it's a commons, a commons tilled and tended by many hands, to bring it to the state it is today.

And so, Sir, lastly, I say you are a thief. You are a thief in that you seek to enclose commons, to deprive the community of the rightful fruits of its labours over many decades, to make property what is not, never was, and never could be property. To steal our work and sell it back to us.

Sincerely

Simon Brooke

Reference to the SCO web site shows that they own certain intellectual property and that they correctly attribute the trademark to The Open Group. SCO has never owned "UNIX". SCO is licensed to use the registered trademark UNIX "on and in connection" with their products that have been certified by The Open Group, as are all other licensees.Open Group

If HP makes HP-UX the odds that HP lawyers are aware of the Open Group License are good! Since they are UNIX95 Registered, Then the obvious reason why they said they are safe is safe against SCO is that they could probably defend that point.

So who is the suspect? Is it just a wording twist saying Microsoft is behind it again? Microsoft is after all a Fortune 500 too.

Yes it was ported, try googling "dcom unix", duh. two relevant links, software ag's entirex dcom on linux product and the Open Group's COMSource program. Granted there's no GPL'd com/dcom out there, wish we could have done that, but we never had the resources or mgmnt buy-in to do so. sigh. Are the ports used? Probably a little. You likely don't hear Microsoft making hay about these because they arrived on-scene just as the big .NOT shift was happening, and this was off-message. and no, it wasn't too hard to port except for sorting out threading, ld/.so, security, and process-model issues... haha, but actually pretty standard porting issues, esp back then when *nix threading was less settled.

OpenUNIX, formerly UnixWare, which is about as modern as UNIXes get

Your humble author suggests that SCO found themselves requiring a multithreaded web server, and as SCO UNIX is based on an ancient version of The UNIX spec it just couldn't cope ;-).

Well, there's a smiley so I know you're kidding.

But there are also some inaccurate facts and presuppositions buried in those comments.

First, your comment appears to ignore SCO's ability to use SCO UnixWare. SCO has two UNIX products, SCO UnixWare, and SCO OpenServer. SCO OpenServer is a Xenix descendent that is singlethreaded and probably as you suggest, couldn't cope. This is what most of SCO's installed base uses, and yeah it's old cruddy technology. SCO UnixWare uses pretty-sophisticated SVR5 technology that is really the core SVR kernel descended from AT&T & Novell days. It's pretty slick functionally (imho), is quite multithreaded running on 8-way (and NUMA I believe) systems, and conforms to UNIX 95 (although not UNIX 98 or the new UNIX 03 tweaks.) SCO is really suing over technology and rights allegedly derived from UnixWare/SVR4-5, not the older OpenServer technology you'd find in 90% of SCO installations.

Second, having a multithreaded webserver that can cope has little or nothing to do with whether one conforms to the latest UNIX specs from the Open Group. But I know you probably know that and are just trying to toss that in there, right?

--LP, not a UnixWare fan, just trying to reduce misinformation on the subject of SCO UNIXes

• Huh?
• 
  
  The Open Group has owned the registered trademark UNIX since 1994

as many readers had noted, POSIX is avaible here, unfortunately, to download it, you shoud accept a licence that states "However, you are NOT permitted to amend, copy, reprint, offer for sale, or otherwise re-use material from these documents without explicit permission from The Open Group/IEEE." (emphasis added by me)

i wonder if "writing an opereting system" to be compliant to this documentation is to "reuse material" and in violation of the licence...

beware what you download and read if you are a kernel developer ;)

Why have you not stepped away from the words "Open Source"?

If you go here there is a venn-like diagram showing that Open Source is a broadly inclusive definition, and how the GPL that you push is a small part of the Open Source universe.

You had said on Techocrat.net:
"It is not the job of Linux advocates to support BSD"

At The Bazzar you said:
'The new BSD licence is great. It allows a GPL license to be added, and the code protected'.

And in the Open Group Open Source document you talk about "Assure that Open Source developers can participate in standards that are operated or facilitated by the Open Group, including the certification programs operated for those standards. This may require a special rate structure or coordination of corporate sponsorship for the Open Source project to go through certification.

Promote broad certification of Open Source software by encouraging certification of a publicly available and redistributable version of an Open Source program, rather than a particular vendor's instance of that program. This will allow multiple Linux vendors to coordinate their activities on certification, so that a larger collection of Open Source becomes certified than any one vendor would achieve on their own. "
This document ignores Open Source running on platforms like Solaris, AIX, AT&T-UNIX-IP-Free'ed-BSD's, or even Windows. How does running on GNU/Linux like platforms make it an "Open Source" program and 'worthy' of certification?

If you only wish to support the GPL and GPLed software, why do you keep using the words Open Source? There is a definition of what you actually advocate in word and deed called Free Software.

You are probably more inclined to than look at this project than POSIX compliance different issue altogether though within the scope of LSB.

POSIX compliance is mainly in the API
while the directory layout is a matter the LSB is approaching it is not part of POSIX specification except for some directories that must exist.
Detail

Both are "unix" as in "unix-like" but neither Linux nor OS X are UNIX in the strict sense. Although if someone wanted to front the cash and a little developer time I wouldn't be surprised if both OS's could be certified.

AFAIK all of the *BSD flavors share the same ancestry, traced back to Berkeley's re-implementation of AT&T UNIX.

It is under this license. I just skimmed it, and my take is that it seems like a free license, except your copyright is always assigned to The Open Group.

So, the Open Group will always own Motif, but you are free to use, modify, redistribute, and sell. Unless I am reading it wrong. I don't feel like looking too closely right now.

According to the Motif FAQ, "On May 15, 2000 the Open Group released the Motif source code for Motif 2.1, using a public license, to the Open Source community. On January 29, 2002, Open Motif 2.2 was released.

For more information on Open Motif, see:

http://www.opengroup.org/openmotif/"

Regarding SCO's positioning on UNIX, The Open Group would like to make it clear that SCO holds the rights only to the operating system source code originally licensed by AT&T and does not own the UNIX trademark itself or definition of what a UNIX system is. [...]

In fact, SCO has never owned UNIX or the definition of what a UNIX system is. From the OSI Position Paper on the SCO-vs.-IBM Complaint:

Neither SCO/Caldera nor old SCO has ever owned the UNIX trademark. IBM neither requested nor required SCO's permission to call their AIX offering a Unix. That decision lies not with the adventitious owner of the historical Bell Labs source code, but with The Open Group.

From http://opengroup.org/:

Who owns UNIX® ?

You may have seen recent press articles announcing that SCO is the owner of UNIX or has licensed UNIX to Microsoft. Such statements are inaccurate, misleading and cause considerable confusion. The Open Group has owned the registered trademark UNIX since 1994. Here is what we said in response to a Linux Weekly News article last week. Also available is a backgrounder that explains the history and reasons why The Open Group takes action on trademark misuse.

The Open Group owns UNIX. SCO just owns the copyright on some old source code that *implements* UNIX and nobody could care less. Furthermore

Regarding SCO's positioning on UNIX, The Open Group would like to make it clear that SCO holds the rights only to the operating system source code originally licensed by AT&T and does not own the UNIX trademark itself or definition of what a UNIX system is. [...]

In fact, SCO has never owned UNIX or the definition of what a UNIX system is. From the OSI Position Paper on the SCO-vs.-IBM Complaint:

Neither SCO/Caldera nor old SCO has ever owned the UNIX trademark. IBM neither requested nor required SCO's permission to call their AIX offering a Unix. That decision lies not with the adventitious owner of the historical Bell Labs source code, but with The Open Group.

From http://opengroup.org/:

Who owns UNIX® ?

You may have seen recent press articles announcing that SCO is the owner of UNIX or has licensed UNIX to Microsoft. Such statements are inaccurate, misleading and cause considerable confusion. The Open Group has owned the registered trademark UNIX since 1994. Here is what we said in response to a Linux Weekly News article last week. Also available is a backgrounder that explains the history and reasons why The Open Group takes action on trademark misuse.

The Open Group owns UNIX. SCO just owns the copyright on some old source code that *implements* UNIX and nobody could care less. Furthermore

This is quite off base in my opinion. Yes I work for Sun, but even if Sun weren't trying to push Linux into the market (which Sun is) Sun recognizes that anything that is unix is better for the market than Windows.

"Compete on implementation, not on control of the specification"

That's been one of Sun's mottos in this area for quite a while (possibly from even before Linux existed)-- and if you really think about it, it's a pretty good one. Sun has applied that kind of thinking to chips and OSs for years (there are other URLs too, those are just two examples). Before "open source" was en vogue, open systems were, and it's worthwhile to think about what the open systems market was all about.

Official standards may have changed since I worked there in 1998, but I doubt if the culture has changed. Which worked like this: we had a choice of two desktop environments Open Look and CDE. Most old Sun hands used Open Look, but IS was trying to end-of-life it, mainly because they didn't want to support mail clients that directly access the mailbox file, as all the Open Look clients do. Open Look users were fighting this change tooth-and-nail.

When I started, I was told to use the IMAP client that's built into CDE. Which was probably as close to a "standard client" as anything that was then in use. It was only after I got sick of the limitations of this program (especially its lack of directory support) that I switched to the Netscape IMAP client all on my own.

http://www.opengroup.org/publications/graphics/n90 0cov.jpg

I think you mean the Open Group who is now responsible for enforcing what "Unix" *is*. Not to be confused with the X Consortium, the keepers of the X11 protocol. Besides, the OP only asked about roots. :-)

Many of the comments in the Linux kernel are from the posix specification which is available on the internet. http://www.opengroup.org/onlinepubs/007904975/

It makes a lot of sense for a developer to copy the specification as comments and fill it up with implementation details. That's the way I would do it! That would explain why comments are the same and code is different.

solaris is a registered unix product, so unix-type would be inaccurate.

for a complete list of what "is" unix, go to open groups registered product listing.

here's the contact information for the Open Group...

http://www.opengroup.org/contacts/

Because Apple did certify MacOS X as a Unix with them.

Oh really? Well, if you can find it in their list of licensees for UNIX 95 or UNIX 98 branding (which is what it would fall under, since nothing's been put up for Single UNIX Spec v3 testing yet, afaik), then let me know. Otherwise, I'm pretty sure Apple never licensed the UNIX name for use with OS X. I believe A/UX was a branded UNIX way back in "the day", but you can't just go jumping from codebase to codebase and take the branding with you.

As far as I can tell, your statement is simply not true. Apple's products are neither Unix 98, nor Unix 95 certified, and a search on google reveals no reports of a press release stating that Apple has met the UNIX certification requirements needed for certification. Surely if such an announcement ever existed, at least one Apple fanboy site would still be mirroring it.Apple is a member of the Open Group, but much of their work seems to be with other committees, such as the School Interoperability Framework committee.

A bird says that would make the year about 1993. It is entirely too bad. The wise bird tells me imperative for growth history is.

In 1987 a few big name companies, DEC, HP, IBM started up OSF because of concern of royalties and control of ATT (basically feeding control back to the small guys ... err IBM is not that small, whatever) who was broken up in 1984 by the US government for their monopolistic nature on the market place. It was definitely an interesting predicament for ATT. Read up on that. Anyway, OSF gave way to all the things you know about then, POSIX rewrite OSF/2, windowing system X11, the GUI MOTIF, distributed computing (DCE), distributed management (DME).

ATT and Sun were expected to join I guess, but joined another team to create the Archer group which I might have to do a google search as I forget what has come of them.

Anyway other shit happened during this time, mostly Unix vendor wars and such and Linux in 1991.

In 1993, ATT sold Unix labs and rights to Novell. Novell knew it wouldn't fare well holding onto the rights when so much force was against them via Open philosophies that they gave the rights of Unix to X/Open. Novell sold their Unix systems (code, whatever) to SCO. In 1996, or near so, OSF and X/Open merged to become The Open Group. The Open Group sets compatibility up, working with IEEE in creating the POSIX standards. The Open Group is all about working in many environments, which was their prime focus of the company during the "unix wars" in the 80s. Unix in english is The Open Group, and in practice, IBM, Linux, OSX, etc.

"Do they make a version of UNIX? Shit, I don't know."

Not exactly. I'm sure you can figure it out now though.

And yeah, I totally think that Unix could be generic now. It is kinda stupid to make a point of all this, but sometimes we need to break from our coding and learn from the past.

I hope my bird has proved informational...

First - The Open Group was created in order to manage Microsoft's " open systems activities"(ActiveX) .

"The Open Group, created this year to act as the holding company for The Open Software Foundation (OSF) and X/Open Company Ltd., provides a worldwide forum for collaborative development and other open systems activities.

The Active Group, to be formed under the auspices of The Open Group, will manage the evolution of ActiveX technologies. It will take advantage of The Open Group services in the areas of development, branding, testing and licensing. The Active Group also will provide a forum for discussion and input on the direction of ActiveX."

Microsoft will provide specifications, source code, reference implementations and validation tests for ActiveX technologies to The Open Group.

They claim to support "standards", but their standards are not W3C type stadards. The Open Group's standards involves "Boundaryless Information Flow":

Any full solution to the Boundaryless Information Flow problem needs to have a chain of technology components, preferably based on open standards, that: - Integrate data - Securely deliver data - Register data - Enable the flow of data - Develop systems that enable this flow of data - Manage systems that deliver this flow of data - Adhere to policies that govern the flow of data

They want to standardize open source to the point of defining process and architecture. Sounds to me like a ploy to curb/control the innovation that is charteristic of the open source community and at the same time distract attention from standards like W3C. Interopablity has nothing to do with the flow, but rather the format of data (apple).

This lawsuit and their copyright is nothing but mickey mouse BS - much like SCO. Is Microsoft be behind both? If they are not - they should be - because the likes of Unix and Apple could sink their boat pretty quickly once they slap palladium in their product.

Yours truly,
Jeffrey Boulier

I'm not at all sure if Linux could pass, since it has, eg, a rename(2) system call in place of unlink.

I'm not at all sure what prompted that. Of course GNU/Linux systems support the unlink system call. You can see the GNU C library implementation of unlink and the Open Group specification of unlink. As GNU/Linux attempts to be compatible with Unix, it would be ridiculous for it to not provide unlink.

To be able to use the UNIX brand, a system must be certified to comply with the Single UNIX Specification (SUS). The SUS typically states what the interface and behavior must be, but not the exact implementation. From the above-mentioned documentation, the unlink system call seems to be compliant with the specification.

The real issue with GNU/Linux systems is certification. Even if they do provide a working implementation of SUS, each release must be certified by The Open Group as compliant. This is reportedly quite a lengthy, expensive process.

That said, there are probably aspects of a GNU/Linux system that do not conform to SUS, such as the varying threading implementations. Lately, however, Red Hat has been encouraging the use of NPTL, an implementation of POSIX Threads, so it is conceivable that someone might try to certify a particular GNU/Linux distribution as UNIX some time in the near future.

I'm not at all sure if Linux could pass, since it has, eg, a rename(2) system call in place of unlink.

I'm not at all sure what prompted that. Of course GNU/Linux systems support the unlink system call. You can see the GNU C library implementation of unlink and the Open Group specification of unlink. As GNU/Linux attempts to be compatible with Unix, it would be ridiculous for it to not provide unlink.

To be able to use the UNIX brand, a system must be certified to comply with the Single UNIX Specification (SUS). The SUS typically states what the interface and behavior must be, but not the exact implementation. From the above-mentioned documentation, the unlink system call seems to be compliant with the specification.

The real issue with GNU/Linux systems is certification. Even if they do provide a working implementation of SUS, each release must be certified by The Open Group as compliant. This is reportedly quite a lengthy, expensive process.

That said, there are probably aspects of a GNU/Linux system that do not conform to SUS, such as the varying threading implementations. Lately, however, Red Hat has been encouraging the use of NPTL, an implementation of POSIX Threads, so it is conceivable that someone might try to certify a particular GNU/Linux distribution as UNIX some time in the near future.

I'm not at all sure if Linux could pass, since it has, eg, a rename(2) system call in place of unlink.

I'm not at all sure what prompted that. Of course GNU/Linux systems support the unlink system call. You can see the GNU C library implementation of unlink and the Open Group specification of unlink. As GNU/Linux attempts to be compatible with Unix, it would be ridiculous for it to not provide unlink.

To be able to use the UNIX brand, a system must be certified to comply with the Single UNIX Specification (SUS). The SUS typically states what the interface and behavior must be, but not the exact implementation. From the above-mentioned documentation, the unlink system call seems to be compliant with the specification.

The real issue with GNU/Linux systems is certification. Even if they do provide a working implementation of SUS, each release must be certified by The Open Group as compliant. This is reportedly quite a lengthy, expensive process.

That said, there are probably aspects of a GNU/Linux system that do not conform to SUS, such as the varying threading implementations. Lately, however, Red Hat has been encouraging the use of NPTL, an implementation of POSIX Threads, so it is conceivable that someone might try to certify a particular GNU/Linux distribution as UNIX some time in the near future.

see WIPO

As to Unix:

Nothing like facts to really mess up your argument.