Apple has previewed OS X 10.6 at this year's Worldwide Developers Conference in San Francisco, code-named Snow Leopard.

A 64-bit operating system, Snow Leopard has theoretical support of up to 16TB of RAM, is optimised for multi-core CPUs, and according to Apple, it is expected to hit the market in "about a year".

Snow Leopard's extended multi-core support comes from a technology named Grand Central, a framework expected to make multi-core coding easier for developers. Apple's increased multi-core support parallels Intel's latest chip developments, which are quickly heading into six- and eight-core territory with its Dunnington and Nehalem processors, due in the next seven months.

Apple is also extending developer support for the graphics processing unit (GPU) through a language called Open Computing Language (OpenCL). Based on C, OpenCL has been "proposed as an open standard" according to Apple, and "lets any application tap into ... GPU computing power previously only available to graphics applications", which means that General Purpose GPU (GPGPU) coding could become a lot more accessible under Snow Leopard.

Other updates include native support for Microsoft Exchange 2007 through the Mail, iCal and Address Book applications, QuickTime X and a Javascript update. Apple claims the improved JavaScript implementation will increase performance in its Safari browser by 53 per cent.

While Apple has confirmed OS X 10.6 will be 64-bit, it has not confirmed whether it will drop the 32-bit backwards compatibility present in OS X 10.5, or whether the PowerPC architecture or the Blu-ray DVD standard will be supported.