Snow Leopard secrets - the tech behind Mac OS X 10.6

The Feedster

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Jun 26, 2007
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Slide past all the iPhone 3G hoopla that’s been around at WWDC 2008 this week and you’ll discover something that’s potentially a lot more significant: Mac OS X 10.6 Snow Leopard.

Although Snow Leopard only received the briefest of mentions during Steve Jobs’ keynote, a follow-up press release and an interview with the New York Times suggests the direction Mac OS X is heading in next.

Publicly Apple is putting the brakes on new Mac OS X features to focus on ‘speed and stability’... which sounds a little dull until you look at the detail.

Welcome To Grand Central

One of the biggest new features of Mac OS X 10.6 Snow Leopard will be Grand Central - a new technology that enables apps running on the OS to take advantage of multi-core CPUs.

Now Mac OS X has been able to use multiple processors since the old PowerPC days, but developers have often struggled to harness their power for use in applications. Steve Jobs confirmed this in an interview with the New York Times on Tuesday:

"The way the processor industry is going is to add more and more cores, but nobody knows how to program those things..."

"I mean, two, yeah; four, not really; eight, forget it."

Jobs says Apple already has the answer - and it’s called Grand Central.

Parallel computing

Since Apple already uses multi-core processors in everything from the MacBook Air to the MacBook Pro, giving developers a helping-hand looks like a shoe-in.

Some have speculated that Grand Central may work by acting as a mediator and controller between Mac applications and available CPU cores.

Grand Central will automatically tell an application what cores are available and then hand them the best resources available.

In other words, all of your Mac apps will run faster, not just a few that have been specially programmed to do so (like Adobe Photoshop CS3).

GPUs tamed

Working alongside Grand Central, will be Open Computing Language (OpenCL) - a new Apple technology that aims to harness the power of modern graphics CPUs and use them for ordinary computer functions.

OpenCL sounds similar to Nvidia’s CUDA, although Steve Jobs reckons Apple’s version will be much, much better. Unfortunately we don’t know much more about OpenCL than that.

Mac OS X and security

One of Apple’s other aims with Snow Leopard is to make Mac OS X much more secure. Apple has already started that process with Mac OS X 10.5 Leopard.

Applications that want to run on Mac OS X have to be ‘signed’ by Apple to ensure that they don’t pose a security or stability risk to either the operating system or the end user.

Apple has also introduced this policy for the iPhone and iPod touch as part of the version 2.0 firmware upgrade, and it looks like it will be significantly enhanced under Snow Leopard.

This suggests too that Apple might want to offer ‘approved’ Mac apps through the same AppStore that it has just announced for the iPhone.

Mac OS X exploits

Apple certainly needs to beef up public perceptions of security on Mac OS X.

Although there have very few real world exploits, there have certainly been some notable and embarrassing breeches in Mac security too.

These range from possible exploits in Safari and QuickTime to news that Apple has been slow to update the open source BSD kernel that lies at the heart of Mac OS X.

That resulted in a hacker taking control of a MacBook Air in minutes during a competition at CanSecWest in March.

No going back?

Apple’s never been backward when it comes to getting rid of legacy technology and that looks like to continue under Snow Leopard.

Apple famously became the first PC make to drop the floppy disk with the original iMac in 1998, ditched its creaking ‘classic’ Mac OS with the advent to Mac OS X in 2001; and then switched from PowerPC to Intel CPUs in 2005.

Apple now looks like it’s going to ditch PowerPC altogether for Snow Leopard, enabling it to strip legacy code out of the OS and focus nearly all its future development efforts on Intel.

Cocoa vs Carbon

It also plans to wrap Mac OS X’s code in a Cocoa wrapper. Cocoa, based on Objective C, is a development environment for Mac OS X that Apple has been cajoling developers into adopting for the last four years.

There are lots of benefits for developers in doing so, but some laggards have been doggedly sticking to Carbon - a hangover from the ‘classic’ Mac OS days.

Apple is evidently hoping that by squeezing Carbon even further it can eventually excise all traces of its code from Mac OS X - only it’ll need to persuade major developers like Adobe to come on side.

Leaner, meaner Mac OS X

Another of Apple’s aims with Snow Leopard is to make the whole operating system much leaner and meaner than the current version.

That doesn’t just mean in power and performance terms, but also in how much physical disk space the OS takes up.

By shedding unwanted APIs and optimising its code, Apple will enable full versions of Mac OS X to be used devices with limited disk space - potentially benefiting the iPhone, MacBook Air and more.

It will also ensure that Apple’s software engineering teams don’t have to struggle to support multiple operating systems for a growing numbers of platforms.

That's exact opposite of what Microsoft’s been doing with the various flavours of Windows, Windows Mobile, etc.

QuickTime X

Another recipient of a Snow Leopard spring clean will be QuickTime, the audio-video technology that underpins apps like iTunes.

The new version, dubbed QuickTime X, leverages techniques Apple’s engineers have developed for the iPhone.

This should hopefully a much wider range of codecs in future, and to it enhance those - like H.264 - that is uses already.

There is also some speculation that QuickTime X will enable Apple to dump a lot of legacy code, leaving it leaner and less vulnerable to malware attacks.

Microsoft Exchange support

Apple is already set to deliver Microsoft Exchange for the iPhone 3G when it goes on sale next month. Now it’s going to do the same for the Mac.

It might seem a strange move for Apple to licence technology from its chief rival, but Microsoft Exchange support is all about getting more Macs into the hands of business users.

The logic is straightforward - give business users what they want on the iPhone, and soon they’ll want other Apple hardware too.

For that to happen, Apple also needs to remove other obstacles to adoption, just as it did by transitioning Mac hardware from PowerPC to Intel CPUs.

The challenge of Windows 7

Ultimately all of the changes are emblematic of how Apple wants to compete against current and future versions of Windows.

Despite some problems, Mac OS X Leopard has positively gleamed when compared to the mess that is Vista, and it’s evidently hoping to repeat that trick again against Windows 7.

By focusing on the core code of Mac OS X rather than on showboating features, Apple can do the hard work it needs to now to develop a solid foundation for future OS versions.

Mac OS 11?

By the time Windows 7 comes out in 2010, Apple may well be touting a version 7 of its own with Mac OS X 10.7.

It could even spring Mac OS X 11.0 upon us - and they’re sure to bring a whole suite of features that will have Microsoft’s engineers slapping their foreheads yet again.

Whatever happens the future of the Mac OS X looks mighty rosy indeed.


Let the speculation begin - your comments below please!