Evolving Apple turns to Darwin

LATE LAST week, Apple Computer released an operating system product that runs on PowerPC chips. And also Intel chips. Intriguing, isn't it, that the company which has from its inception used Motorola processors should be writing software to run on the chips that normally run Windows - and, increasingly, Linux?

What it might mean is that in a few years from now you'll be able to buy PCs which run Apple's next-generation operating system, MacOS X. You might even be able to buy just the operating system and run it on your present PC.

More likely, you could buy an iMac in the future and discover somewhere in the small print that it had an Intel or AMD chip powering it, rather than a Motorola/IBM PowerPC chip. Not that you'd notice any difference.

For a moment let's leave the question of "Why?" and deal with the question of "How?" The product released last week is Darwin 1.0, and Apple calls it the "operating system core" of MacOS X, due for release (on PowerPC chips) this summer.

Darwin is Apple's venture into a limited form of open-source development. It's not as open as Linux, where everyone gets to see all the source code; nor as closed as Windows or the present Apple OS, where developers are just told what "applications programming interfaces" are available. Darwin lies somewhere in between: the wider net community offers suggestions on development, but the hard work is all brought together at Apple's headquarters in Silicon Valley.

MacOS X pulls together the work Apple has done over the past 16 years developing its graphical operating system for Motorola-made chips with that of NeXT, the computer company it bought in 1997. NeXT ran on Intel and Motorola chips, with a Unix-like "kernel". MacOS X is more like Unix than many people would like to admit. That gives it the flexibility to be transported to other chips.

It was at the end of March that Wifredo Sanchez, an Apple software developer, posted a little note on the Apple Darwin bulletin board saying: "Wednesday - the whole thing compiled for the first time for both PowerPC and Intel." A trifle shy, maybe, but there were probably cheers in the boardroom.

Why? Ah yes, the big question. It's not that Apple is looking to license its operating system to PC makers. "Cloning" on Motorola-based machines almost killed Apple off, and Steve Jobs stopped it as soon as he took over. But Apple has problems. In April last year rumours began circulating that Intel was "courting" Apple. IBM and Motorola - which design and make the PowerPC chip - had begun arguing about the future. Motorola reckons the PowerPC can't win in the PC market, and wants to focus on the "embedded system" (in cars and household items like set-top boxes) market. IBM reckons it can flourish in the server market. Disagreement has hurt the supply chain, especially of top-end PowerPC chips. So if Apple could get MacOS X to run on Intel chips, it could solve some of its supply hassles at a stroke.

Apple notes though that to bring Darwin, and ultimately OS X, to Intel chips still requires work on "drivers" - the software which gets the operating system to talk to printers, keyboards and mice - and "platform support", a rather hazier concept which includes making the code use the processor efficiently.

The end result of that little posting by Sanchez is probably years away. You can buy Apple's operating system off-the-shelf today; trouble is it won't run on a PC. But if MacOS XI, say, is developed to run on all sorts of chips, why shouldn't you install it on your PC?

carthur@independent.co.uk