Uncharacteristically bowing to the needs of its customers, Apple Computer Inc. last week changed its mind on a policy announced in September declaring that as of Jan. 1, all new Macs would boot into only Apple's OS X software.

To assuage concerns about lost functionality, Apple has reminded customers that although the OS X-only Macs won't boot directly into OS 9, most older programs will run in "Classic" mode, which launches a version of OS 9 after the Mac has booted into OS X.

Essentially, both old and new systems run at the same time, but it's not a perfect solution: Some OS 9 programs run poorly in Classic mode; a few, not at all.

Apple's reversal Friday addresses two groups of customers who need to be able to boot directly into OS 9: professional users who rely on the publishing program Quark Xpress and schools.

Until next June, professionals can buy a top-of-the-line dual 1.25-gigahertz G4 tower -- current price: $3,299 -- that will retain dual-booting capabilities. Education customers will continue to have available certain eMacs, iBook laptops and original-design CRT-based iMacs with OS 9-booting ability.

But Apple's Dec. 13 announcement rekindled consternation on the part of some Mac users concerned about losing the ability to boot into OS 9 on their next Mac, and precisely what Apple's policy means.

Users were worried that every Mac built after Jan.1 would lack the ability to boot into OS 9. In fact, an Apple spokesman said that existing Mac models will, indeed, retain the ability to boot into OS 9 after Jan. 1 -- and won't become OS X-only until Apple revises the model.

Thus, only Mac models upgraded in January will lose the ability to boot into OS 9. As models are revised over the following months, they, too, will lose the ability to boot into OS 9.

The good news, however, is that Mac users looking to buy a machine -- and they're agonizing over whether to buy now to ensure getting an OS 9-bootable Mac -- can relax a little. Some dual-boot Macs will continue to be available into the first part of next year, although no one but Apple knows which models or for how long.

In this context, Apple's statement appears more of a reassurance to two of its primary market segments that have specific reasons for needing to be able to boot into OS 9; such machines will be available to them until June, regardless of which models Apple upgrades over the period.

Graphics and publishing professionals, long a staple of Mac's market, have hesitated to leave OS 9 behind because Quark Inc., alone among the major programs these professionals rely upon, doesn't have an OS X version of Xpress -- yet.

Apple, based in Cupertino, Calif., has reason to be concerned that it could lose publishing customers because of the late OS X version of Xpress. A Nov. 27 response from Quark's communication manager, Glen Turpin, to Mac users questioning the company's commitment to the Mac shed some light on the Quark-Apple relationship:

"Our market data indicates that fewer publishers are purchasing Macs," Turpin said, "and more of our Mac-using customers are considering switching to Windows."

Turpin, however, said that Quark remains committed to the Mac platform and that Mac users still constitute a majority of Quark's customer base. He added that the relationship between Quark and Apple is "closer than it has been in years."

Turpin didn't specify when the OS X version of Xpress would appear, saying simply that "there is still a lot more testing to do before we release it."

Educational customers have avoided switching because many school systems still have a lot of Macs that are too old to run OS X (basically machines five years and older). Even those schools with Macs that can run OS X have found that some educational CD-ROMs written for OS 9 won't work in Classic mode.

Many ordinary home users also have reasons for wanting to retain the ability to boot into OS 9. Besides legacy software that won't run in Classic mode, some Mac users -- myself included -- have discovered that certain peripherals, particularly older scanners, won't work unless the Mac is booted into OS 9.

So any Mac user who requires the ability to boot into OS 9 and who was planning to buy a new Mac within the next nine months will need to pay strict attention to Apple's new product announcements -- unless they're a well-heeled graphics pro or an educator.

Of course, a practical solution to the OS 9 booting dilemma is to keep your old Mac after you've bought a new machine.

But why is Apple causing such headaches for its loyal customers?

The answer is simple: the company has bet the farm on the new operating system and needs both its software developers and its customers to switch to OS X as quickly as possible.

Apple CEO Steve Jobs made this clear when he first announced the OS X-only policy Sept. 10 at the Apple Expo in Paris.

"Now, it's time for Apple and our third-party developers to focus all our resources exclusively on Mac OS X," Jobs said, "rather than dividing them between two different operating systems."

If Apple's September projections are accurate, approximately 20 percent of the 25 million Mac users worldwide are currently using Mac OS X, which first appeared as a public beta -- an unfinished but usable test version -- two years ago.

That means 80 percent still are using Mac OS 9 or earlier, either because the model they own doesn't support OS X or because they prefer OS 9.

Apple's challenge has been to convince developers to write software for the new OS, while the majority of Mac users are still on OS 9.

Meanwhile Apple has been pushing users to switch to Mac OS X, which was a tall order 18 months ago when far less software had been converted to OS X.

Apple expended much effort this year trying to move all parties over to OS X.

At the Worldwide Developers Conference in San Jose, Calif., in May, Jobs showed a boxed copy of OS 9 in a coffin, saying to the hardware and software developers, "Mac OS 9 isn't dead for our customers yet, but it's dead to you."

One major way Apple has tried to nudge Mac users is with OS X-only versions of its newest free applications, such as iPhoto and iCal. The company also released OS X-only updates to "iApps" such as iTunes and iDVD that previously had versions for both Mac operating systems.

It's regrettable Apple feels it necessary to use such heavy-handed tactics, but it also indicates the degree of urgency the company feels to complete its transition to OS X.

As inconvenient and burdensome as this transition will be for some, OS X is undeniably the future of the Mac platform. Virtually all Mac users will have to adopt it, sooner or later.

Even without OS X-only Macs, the growing scarcity of new OS 9 software and decreasing support for it will make staying with OS 9 ever more untenable.

As with past Apple transitions, including the Apple II to the Mac and the shift to the PowerPC – the road from OS 9 to OS X will have its bumps but the destination should prove worth the trip.