A lot of feedback flowed into InformationWeek after our Jan. 23 cover story, "What's Left Of Unix?" Most of the responses offered full bore support for Unix, as in, "Not meaning to be harsh, but man... wake up guys!!""Like every other Linux/Unix story, you also failed," began Ed Taylor, an independent consultant, 30-year IT veteran, and former CIO somewhere on the coast of North Carolina. "IBM, HP and Sun sell and support tons of boxes... And to think this was an 'In Depth' article..." he wrote. Ouch.

Taylor and other writers have pointed out that Unix as an operating system is not disappearing because of Linux. Linux is Unix. "At no point in the article did you mention that Linux is in fact a conformant implementation of Unix... It's only the proprietary, closed-source Unixes that are having trouble," wrote Dan Kegel, a software engineer for Google in Los Angeles.

An earlier version of the story referred to Linux and its "big brother" Unixes, meant to suggest Linux's direct connection to the more muscular and mature Unixes, but the relationship got lost in the shuffle. It's still there later in the story, when we said, "Solaris now shares with Linux the distinction of being the Unix that runs best on Intel hardware." But this is a subtle statement rather than a plain one. Mea culpa.

Then there's the writer, going simply by David, who points out we didn't mention the new Apple Mac operating system is based on Unix. "I think your article was a little uninformed... How, I ask you, can you leave out OS X and Apple?"

"Not meaning to be harsh," he continued, "but man...wake up guys!! Trust me. I'm not a disgruntled Mac-head by any means, but I DO know a massively growing technology base when I see it."

It's hard to argue with much of this feedback. When we asked, "What's Left of Unix?" we were clearly addressing commercial, data-center Unix that still commands a handsome price tag.

Yes, Linux is a form of Unix that owes a great debt to its predecessors, but Linux is something the older Unixes are not. It is a Unix designed for common denominator hardware. Linux is free and the hardware on which it runs is cheap. A short while ago, neither Unix nor the hardware on which it ran was cheap. Linux's ability to run well on Intel hardware made it a preferred system among developers who didn't happen to have an expensive workstation in their basement. Linux grew from this foothold among developers into a marketplace force and is now found in the data center alongside the commercial Unixes.

And Sun is the first mature Unix vendor to try to follow Linux across this threshold. Sun appears to be succeeding in this move, so Unix as open-source code will have two tiers: popular Linux at the base and Solaris with a more limited community above it.

The letter that I liked best came from Dion Johnson in Scotts Valley, Calif., who used to teach Unix classes at SCO and is a former product manager for SCO OpenServer. He's now a board member of Wireless Cables Inc. "Unix is a technical/cultural heritage, not a product," he wrote.

Even Microsoft's DOS and Windows owe many of their structures and concepts to Unix, he says. "How much of DOS was copied directly from Unix (it's a work-a-like)?" he asked. "Just look at the commands and file structures, etc. DOS looks like a feeble-minded Unix, and Windows looks like DOS with windowing and networking added."

I would go a step further and say the Internet is laced with Unix conventions and structures. Without Unix, we wouldn't have the World Wide Web and the file path that leads us to our favorite URLs. Unix or Unix concepts are now embedded all around us. It's not dead. It has succeeded so well that it's become part of the landscape.

"The point is, it's all evolutionary," Johnson concluded.

I couldn't agree more.