Was it a full 10 years ago that Apple debuted a brand-new operating system called Mac OS X? It may be hard to accept that, mainly because that would involve accepting the the fact that we’ve all aged a decade as well.

But it’s true: On Saturday, March 24, 2001, Apple’s long-awaited, desperately-needed replacement for the aging “Classic” Mac OS arrived in stores. Apple’s press release features a quote from Steve Jobs--”the most important software from Apple since the original Macintosh operating system”--that might have looked overblown at the time but in retrospect is accurate.

Without OS X, Apple might have held on long enough to introduce the iPod and then the iPhone. But its job would have been much harder. And personal computing would have been a good deal less pleasant for Mac owners. As I noted in a column I wrote for OS X’s fifth birthday, Apple got three things right from the start: The system is separate from everything else; each user’s files are separate from everybody else’s; each application acts as one, indivisible file.

But in 2001, the virtues of the $129 copy of OS X 10.0 were not as obvious. It was great that Apple had finally broken a long losing streak in operating-system development--such past attempts as the Taligent and Copland projects had all wound up getting unceremoniously dragged to the Trash.But in the review that ran on March 23 (a friend had given me an advance copy), I couldn’t recommend OS X to most tinkering types: “With Mac OS X, Apple has built an impressively solid foundation for the future of the Mac experience. Unfortunately, the rest of the structure isn’t quite up to code yet.”

The rest of the review makes for interesting and sometimes unfortunate reading. In retrospect, I spent way too much time worrying about OS X’s Aqua interface; all those glowing buttons have long since been toned down or scrubbed clean. And the Dock, after numerous tweaks to its design, became such an effective interface that Windows 7’s taskbar now works like it.

I also fretted too much about application compatibility. Mac developers did a far better job of rewriting their software for OS X than I’d expected--when Apple ditched the “Classic” compatibility environment in 2007, hardly anybody minded.

In complimenting OS X first for its stability--this was the first time in years I’d spent four days plugging away at a Mac without having a system crash--I had the right idea. I was also correct to commend Apple for letting users install and remove programs just by dragging single files instead of fussing with installers and uninstallers as in Windows. But I didn’t and couldn’t know then that OS X would also make for a much lower-maintenance operating system than Windows. It’s a rare Mac problem that requires reinstalling OS X--and even then, you shouldn’t have to reinstall your programs or reload your files.

But that column never once mentions the word “security”--just as my review of Windows XP failed to include that key word. We’ve all had to learn a lot about that topic over the last 10 years, much of it unpleasant.

The full text of that 2001 column appears after the jump; give it a read, then give your own review in the comments.

With Mac OS X, Apple has built an impressively solid foundation for the future of the Mac experience. Unfortunately, the rest of the structure isn’t quite up to code yet.

The $129 operating system, which goes on sale at 12:01 a.m. tomorrow, is Apple’s first “modern” consumer operating system -- that is, the multitasking, crash-protected computing environment that Mac users have been waiting years for.

But Mac OS X isn’t done. It needs bug fixes, some interface refinements, better hardware support and -- most important -- more and better third-party software. For now, what you get is a technically impressive mix of glossy Mac interface and sturdy Unix underpinnings that mostly fascinates and sometimes frustrates.

The good news is, OS X is as stable as Apple promised: In four days of intensive testing, I’ve yet to have the system crash, even as individual programs have self-destructed numerous times.

Other operating systems deliver this kind of protection -- but you can’t install them in 30 minutes or less without memorizing the manual, as OS X allowed me to do on three different Macs. (It requires a G3 or G4 Mac, including iMacs but excluding the first G3 PowerBook, with 128 megabytes of memory and 1.5 gigabytes of disk space.)

Nobody can argue about the utility of a computer that doesn’t crash. OS X’s Aqua interface, however, is more controversial. Where the traditional Mac desktop is mostly angles and edges, Aqua is a soft, shimmering thing, with colorful buttons that glow and pulse to get your attention and translucent menus and windows that add a sense of depth to the desktop view.

Aqua’s most prominent feature is the Dock, a strip of icons along the bottom of the screen that shows active programs, shortcuts for launching others, minimized windows (which whoosh in and out of the Dock in a nifty animation) and some system controls, plus the traditional trash-can icon. If you minimize a QuickTime movie into the Dock, it will even continue to play there.

As all these items land in the Dock, it expands to fill the bottom of the screen and its icons shrink, but you can set the Dock to enlarge them as you slide the cursor over them. These visual tricks look best on a fast Mac; a 266-MHz G3 desktop staggered under the load.

Problem is, many Mac applications assume that the whole screen is available for their use. So when you create a new document, the bottom of its window is obscured by the Dock until you resize it to fit -- a drill I’ve gotten plenty of practice on this week.

The Aqua interface changes many other aspects of Mac behavior, from the way an application handles multiple document windows (they no longer reside in one layer, but interleave with those of other programs) to keyboard shortcuts to your ability to rename or move certain folders. OS X’s dialogue boxes for opening and saving files don’t let you sort lists of documents by anything but name, while Mac OS 9 also allows you to view the newest items first. And drag-and-drop -- the ability to grab some text or an image, then shuffle it from one application to another or to the desktop -- now requires you to click and hold your selection before you move it. All this will take a lot of getting used to, even if the changes may make the Mac easier to use for newcomers.

Aqua does offer more flexibility than the inflexible version we saw in the preview version of OS X. You can now quickly and easily customize toolbar buttons in Finder windows and add shortcuts to folders and drives to the Dock for rapid access to items you’ve squirreled away deep inside the hard drive. This is in keeping with the Macintosh way, and a hopeful sign for future improvements.

Beneath those looks, OS X makes other smart additions to the Mac environment. It tightly integrates multimedia, speaking MP3, QuickTime and PDF (Portable Document Format) as fluently as it does plain text. Its Unix infrastructure lets multiple users easily share one machine and allows technically inclined folks to tweak their Mac in ways impossible under the old regime. Installing, moving and deleting applications is easier, thanks to OS X’s use of “bundles” to package all the files a program needs into one special folder that the system displays as a regular file. And “services” allow one program to offer its tools for use in others; for instance, one service lets you grab text and open it in an editing program.

The weakest link in OS X is its tie to the past -- the “Classic” compatibility environment for running old Mac programs. These applications don’t take on the new Aqua interface and also don’t get OS X’s crash protection: If one Classic app crashes, the other Classic programs die with it. (You can continue working in OS X throughout the crash, although the Dock itself can get hung up until Classic resets.) Switching from Classic to OS X-native programs got less perplexing and annoying after a couple of days, but I don’t think I’ll feel comfortable with it anytime soon.

Unfortunately, some popular programs barely function or don’t run at all in Classic at all -- to name some big ones, Connectix's Virtual PC 4 and Apple’s iDVD and iTunes. Apple pledges updates to its own programs to make them OS X-native (starting with iTunes and iMovie tomorrow), and other vendors are following suit. Their work is badly needed; the supply of OS X applications is limited, and the supply of good OS X applications is even smaller.

I’m going to keep OS X away from my everyday machines while Apple and its developers continue to compose this unfinished symphony. I recommend you do the same, unless you have a taste for adventure and a broadband connection to download all the bug fixes and updates. Otherwise, relax. You’ve waited seven years for this; what’s another few months?