I've gotten in the habit of just writing *nix when distinguishing from Windows.

Isn't necessary to break the distinction down further, until it IS necessary, of course. The user experience is very similar on all of them. Differences don't really surface until you get to a level below that of the ordinary user.

From a UNIX Admin since 1991: Linux is a clone of UNIX written from the ground up. Most other UNIX variants are derivations of the original UNIX with a lot of add ons (e.g. NFS/NIS written by Sun but adopted by most variants).

That's UNIX in caps.

From a user point of view Unix and Linux are the same in my view. That is to say they do essentially the same thing in general using mostly the same commands. They differ only at the nuts and bolts administration. As others here have pointed out those differences occur in the variants of UNIX and in the distros of Linux. The SAM GUI on HP-UX is not the same as Smit or Smitty on AIX and neither is like Admintool on Solaris. However apt-get on Debian isn't the same as yum on RedHat either.

For the experienced Linux user or admin using UNIX isn't that hard and vice-versa. However just as there is a learning curve going from Solaris to HP-UX there is a learning curve going from any of the UNIX variants to Linux and vice-versa.

The one downside I see to Linux users coming up to speed on UNIX is the fact that many Linux users now seem to rely heavily on the GUI desktop because they are ex-Windoze users trying to do it the way they did in that OS. This increases the learning curve because the real power is at the command line and I've seen a fair number of newbies that seem afraid to do commands there.

To me the beauty of UNIX even if you have to pay for it is you have choices of vendors. Linux adds even more choices. Compare that to a monolithic MicroSoft and I've never been able to explain why anyone would choose MS for servers.

P.S. Saying Windows is like UNIX is a bit like saying the a Piper Cub airplane is like the Space Shuttle IMO.

It would be closer to say that DOS was a little like UNIX (in fact the old joke from AT&T who originally wrote UNIX was that MS-DOS stood for "Microsoft Stole our Damn Operating System") because it was command line intensive. However DOS didn't have multitasking or multiuser or networking in general. However the first SCO UNIX I worked on had both X Windows and TCP/IP as add on packages (which we didn't use by the way).

UNIX is a trademark, whether in uppercase or not, so you cannot legally use it as a generic term. The reason why *nix or unix-like are often used. Of course, I'm sure the Open Group isn't going to sue anyone for using it this way in a forum.

The sentence about Windows being UNIX compliant was only a theory, Windows is not complying with the UNIX standards, while most Gnu/Linux distributions are much closer.

The first Unix I used at work (version 7), didn't have networking, X11 or any graphic layer at all, not even vi ... but was already far superior to MS-DOS.

Version 7 of what?

UNIX (the official AT&T stuff) was System blah Release blah with the last real one being System V Release 4 (SVR4). HP-UX Had it's own versioning scheme (7, 9.05, 9.07, 10.01, 10.20, 11.00, 11iV1, 11iV2).
Sun OS had its thing e.g. 5, 6, 7, 8, 9 10 with Solaris being the full OS with X etc... so Solaris 2.5 was SunOS 5 with all the bells and whistles and so on until they dropped the the 2. and just started calling it Solaris 8, Solaris 9, Solaris 10 because no one uses just SunOS any more. SCO Unix had their versioning based on SVR3 so originally had 3.2.2 which was SVR3.2 version 2 but then when they went to SVR4 they named it 3.2v4.2. After they bundled in X etc... they started calling it OpenDesktop and changed versions based on that naming. RedHat is nice - they had versions up through 9 then diverged to the commercial RHEL so started over with version 2, 3, 4, 5. What will be nice is Fedora Core is up to 6 which means RHEL 6 should be out soon. There seem to still be a fair number of people using RedHat 7.3 (Valhalla) so it will be fun when there is a RHEL 7 because newbies often don't know the difference. Questions about one may get misleading answers if they aren't clear. Of course a lot of newbies post the kernel as the release anyway.

I think it was clear from my post I was saying UNIX in caps as an "official" designation and Unix without the CAPS as a generic. Sure, whoever owns the name UNIX (Novell or SCO) might rail against that usage much as Xerox rails against the usage of xerox to mean photocopy. However that won't stop it from happening.

I think the main thing newbies are trying to figure out when they ask the "are UNIX and Linux the same thing" is whether they can easily work on the other if they know the one. It seems highly unlikely they're really asking about who holds the trademark for either name IMO.

I'm talking about official UNIX versions.
You are missing the first part of the history. UNIX started with version 1 as an internal Bell labs project. Version 7 was the first release to be commercially available. BSD started by forking version 6 then 7, while System III was built after version 7.
Later, SystemV Release 4 merged BSD and previous System V features.

Version 7 was considered by many to be the best Unix version ever (better than previous but better also than next releases ...)
Again, you aren't allowed to do that, just like you can't write any "cola" is a "Coca-Cola", or a car is "Ford", as already stated by chort.
Neither of them, the Open Group currently own the brand.
That is unfortunately true. I was puzzled when I first listened to that verb in the US. I believe most non English languages have a proper term for it (French use "photocopier").
I wasn't discussing that much about the trademark, but about what UNIX means, i.e. complying with a set of standards.
Linux, from its creation, was designed to mimic as close a possible a real Unix implementation, so my answer to the OP question is: Linux is almost UNIX compliant, but it isn't completely. Depending on how close you look, the difference may be negligible or huge. Moreover, the standard doesn't define everything but only a common subset of features, so in many areas there are large and uncompatible differences between UNIX compliants systems (say AIX and Solaris), not to mention the differences that can be found between different Gnu/Linux distributions.

As to what I'm allowed to do - I guess I won't leave that up to you. If we really want to be technical about it we should be putting the the R in a circle to show its a registered trademark any time we use it. Since I'm not doing it for commercial reasons I doubt anyone is going to be able to make much of a case on trademark infringement against me.

The English verb is "photocopy" or even "duplicate". The noun is photocopier. Oddly enough "xerox" doesn't seem to be used quite a much as it was a few years ago - I suspect mainly because Xerox is not as dominant in photocopiers as it was once upon a time.

Some people see similarities and the big picture and some people see differences and details.

Joel

Having seen your quote before:
I'm curious since I've not used Slackware in a long time - why don't you consider it Linux? Does it have BSDisms in it?

i am a slackware user too. i think its simpler, faster, but not for end users.

yes, i believe its a :Pengy: too.

Nothing in my signature indicates that Slackware is not Linux. Yes it is structured much like BSD, the most salient example being the startup process. This makes it quite easy to configure the startup process.

The thrust of the point is that Slackware has many characteristics that make it UNIX (with capital letters!) like. I used UNIX more than ten years ago when I first started using the internet, and since finding Linux about a year ago, using Slackware felt like coming home.

The main point of adding on to the "Linux is for people who..." quote (which is from the FreeBSD website) was that Slackware strives to be UNIX-like and therefore it suits both kinds of people (of which I am both). I really liked FreeBSD, but I had some trouble setting it up; Linux helped me get my "feet wet" and once I felt comfortable, having used PCLinuxOS for a while, I went with Slackware. I really like it. I'm using it right now. Not just because I hate Microsoft (which I do), but also because I love using Unix. Slackware is close enough.

Joel

OMG... i needed about half an hour to read all ur posts. Well it's look like it'll be better for me to stay on Linux.
Obviusly Unix (and all what consist of this word) has little too big circle of knowledge to study all, so i'll make my self happy with Linux.
Tnx anyway for help, new i least know the answer if anybody ask me what is Unix.

Thnx and greets.

Wait! I just thought of another analogy...

Unix is like Kleenex ;)

Joel

Cute. Reminds me of various vendor specific Unix variants I've run across in my career.

Xenix, Qnix, Astrix, Dynix, etc...

Astrix - NEC UNIX believe it or not.

I find the differences in Solaris' IPF and Linux' iptables quite
significant. My knowledge of iptables and the way inetd is configured
in Linux doesn't help me in hardening a solaris box all that much...

You're right, linux, solaris (AIX, HP-UX) all will have some sort of
grep, find and awk, for example, but as far as I'm concerned the ones
that come with linux are way more usable :}

I've never had GNU awk swear at me about too many lines of input, while
the default awk in Solaris 6-10 quite happily does. The find in Linux
will allow me to search for names case-insensitively, while the find
in solaris is a pain in the proverbial and forces me to use a rather
verbose regular expression to search for something trivial.
find . -iname "apache*"
find . -name "[Aa][Pp][Aa][Cc][Hh][Ee]*"

Where's the fun in that?! :D


Cheers,
Tink

This is exactly the kind of "caring" I was talking about. If I were in your position, I would find huge differences, maybe even some that would make me prefer Solaris or other commercial Unix. In my position, I like Linux because it serves all my needs and it's less expensive. For right now that's all that matters. Plus with all the distros to choose from, I've found everything I need: the system I have at home (PCLinuxOS)is different enough from the one I have here (Slackware) to satisfy the different demands, yet they're both Linux, and they produce the same familiarity I had with UNIX for me to feel good using it.

I really like GNU software, too. In Revolution OS, the founder of VA Linux (I'm forgetting his name) explained that when he was in grad school, he would spend days downloading GNU software onto brand new Sun machines, because it was so good.

Well, I have to go use some of that GNU software...

Joel