We've known it was coming for some time now, but Apple have officially announced Mac OS X 10.7 "Snow Leopard" at their WWDC 2009 keynote today. Set to be priced as a $29 upgrade for existing Leopard users, Snow Leopard - which will only run on Intel-based Macs - brings with it faster performance, Microsoft Exchange 2007 support, QuickTime X and OpenCL support.
While the GUI of the Apple Finder looks the same, underneath it's had a full rewrite in Cocoa; that makes it faster - Apple say 90-percent of the OS has been refined - with icon previews faster, animations improved and trash emptying quicker, among other things. Expose has been integrated into the Dock; you can show the active windows of any one app by clicking and holding its icon in the Dock.
Thumbnails have been improved, with browsable PDFs, playable videos and deeper Stacks which can handle content. PDFs also have better text selection, while QuickTime X supports color sync, hardware acceleration, HTTP streaming and compatibility with any server based on the HTTP standard. The UI of QuickTime has had a makeover too, with controls and borders fading away to leave only the video content itself. Simple video edits can be made directly in the QuickTime window, by dragging the ends of the clip region, then exported to MobileMe and shared.
Exchange support brings Mail, iCal and Address Book up to speed with Exchange 2007 servers, autodiscovering the server via just your email and password and then synchronizing. Spotlight searches through Exchange messages, and all the existing folders, to-do and note items are brought over too. Invitations and room availability is also supported, and you can schedule a meeting by dropping a contact into iCal.
Snow Leopard also brings support for multi-core systems and true 64-bit, with a new "Grand Central Dispatch" for dealing with multi-threading and new system-wide APIs and an object-oriented framework. Apple demonstrated this with Mail, which under Snow Leopard uses fewer threads when idle and improves responsiveness. All of Apple's core apps are now fully 64-bit. Graphics, too, have been addressed, with OpenCL: that delivers hardware abstraction, c-based language, automatic optimization and numerical accuracy, and is an open standard that all the major GPU companies have signed up to.
Snow Leopard will arrive in September, priced at $29 for an individual upgrade for a Leopard user, or $49 for a family pack.