A week before Mac and iPhone developers convened for Apple's annual (WWDC) in June, there was barely a hint that the company would announce a successor to its flagship operating system, Mac OS X 10.5, Leopard, which was launched in October 2007. Just before WWDC, there was only the rumor of a new Mac OS X version in the works. During the WWDC keynote, however, , the next generation of Mac OS X; it's due out by mid-2009.

The announcement made few waves for most Mac users, and Apple said the new operating system will offer few new features. With Snow Leopard, Apple will focus on performance and code bloat -- aiming to speed things up and reduce the amount of hard drive space the software required.

For developers, these under-the-hood changes (which include advanced support for systems with multi-core processors, OpenCL and the ability to use graphics processing hardware for general computing, and expanded 64-bit processing support) are a big deal. The result should be a leaner and significantly faster operating system.

Apple also appears to be aiming Snow Leopard at the enterprise world. Like the iPhone, Snow Leopard will feature support for Microsoft's ActiveSync protocol, enabling native integration from the bundled Mail, Address Book and iCal applications. Although some Exchange support has been available to Mac users through Apple's Mail and Microsoft's Entourage, it has been largely limited to date -- and clumsy to set up.

The promise of Macs that interact with Exchange as seamlessly as Outlook on a Windows PC will be big news for many users and businesses, perhaps making Snow Leopard one of the most important Mac OS X releases to come out of Apple since the early days of OS X.