Columns for OSOpinion.com

Classic, Carbon, Cocoa, and Compatability

Published on OSOpinion.com on June 5, 2001
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Mac OS X is an astounding piece of work. It is built atop a solid UNIX foundation, yet installs effortlessly, is almost as easy to use as the original Mac OS, and has all the glitzy eye-candy of a Hollywood blockbuster. It gives users the freedom to run software built for Mac OS 9 and below inside the Classic environment, while offering developers a choice between modifying their existing programs to run natively inside the Carbon layer or easily writing programs from scratch with the powerful Cocoa APIs developed at NeXT.

Today, Mac OS X seems fairly stable and usable--the beta version worked better than expected, but it had serious shortcomings that made it unusable. The final release fixed most of the problems in the beta, and subsequent updates fixed much of rest. However, many Mac-users are hesitant to switch to Apple's shiny new operating system. It leaves one asking, why would anyone choose to stay with Mac OS 9 and below? There is an important reason for this, but there is little Apple can do about it. Here is why.

The Classic Ball and Chain

Adobe Photoshop, Microsoft Office, QuarkXPress, and most other programs Mac-users rely upon still have to run in Classic mode. This is a bad thing for Apple--the Classic layer is hardly an ideal environment to run any program, especially those used most.

Many have compared the Classic layer to 68k emulation under the earliest PowerPC machines. This is not an accurate comparison--the 68k emulator was stored invisibly in the machine's ROM, and a Mac user could rarely tell if a program was PowerPC-native unless the software's packaging said so.

Running Classic is not just painfully obvious on Mac OS X--it is a tremendous burden. It means running two operating systems at once, and this demands huge quantities of memory. Running only a few memory-demanding programs in Classic will often leave a machine "thrashing" its hard drive, relying on virtual memory to pull through. Furthermore, programs in the classic layer do not benefit from Mac OS X's superior multitasking and memory management, which leaves a user asking, "Why not just use Mac OS 9?"

Carbon-based Life

The solution for this problem is simple: in order for Mac OS X to be a truly adequate replacement for Mac OS 9, key players like Adobe, Macromedia, Quark, and Microsoft have to make their software run natively on Mac OS X.

Fortunately, these developers have pledged to do just that. Naturally, Apple has been leading the pack, delivering carbon versions of iMovie and iTunes, and Apple subsidiary FileMaker has also delivered a carbon version of its database software. While Adobe promises that the next versions of its most popular software packages will run natively on Mac OS X, only Adobe's Acrobat Reader runs natively thus far. Microsoft is "targeting" a fall release for a native version of Office, but admits it will "take some time" to "do it right." Although Quark is "firmly committed to developing products native to the Mac OS X," the 5.0 release of QuarkXPress will be Classic-only. Macromedia, however, has delivered more than lip-service, recently introducing a "carbonized" version of its popular graphics program, Freehand, and promises more to come.

Is Cocoa hot enough?

The native software the aforementioned developers are promising will likely be "carbonized" instead of "cocoafied," and some think that this is a mistake. The carbon Finder program in Mac OS X has been sharply criticized for being slow and laden with bugs, a problem some say stems from flaws in the carbon layer itself. Others argue that the carbon layer is a temporary fix, and developers should instead focus on building applications with the Cocoa APIs.

Unfortunately, the cost of completely rewriting an application like Photoshop in the Cocoa environment outweighs any additional sales a Cocoa Photoshop might attract. Additionally, a Cocoa Photoshop would have to run on Mac OS X, leaving users with older machines out in the cold and cutting deeply into sales.

While adapting software for the Carbon environment is hardly the tweak Steve Jobs promised it would be, it is the only feasible solution for the time being. If a "carbonized" Photoshop can run without crashing, that will probably be enough for Adobe.

Looking Forward

It is unlikely that Mac-users will adopt Mac OS X as their primary operating system until the software they use daily becomes native, but Mac-users are a patient lot, and they will eagerly wait for the day they can use Mac OS X without once seeing that orange 9 bouncing in their docks.


Matt Johnson is a graphic design student and tutor at a small-town college in Nebraska. He has been using a Macintosh since its debut in 1984, when he was six years old.