The first-ever public Mac OS X (pronounced "10") demo was greeted with cheers and gasps of amazement by the 4,000-strong audience as Apple iCEO Steve Jobs toured the next-generation operating system and its new user interface during his keynote address at Macworld Expo 2000 in San Francisco.

Mac OS X - which Jobs said "will bring the Mac legacy into the next century" - will have a new user interface dubbed "Aqua" and will be rolled out over the year. The operating system is designed to make computing easier for consumers, while simultaneously extending the functionality for professional users. It will fully replace the current generation Macintosh operating system over the next 12 months.

"Mac OS X will delight consumers with its simplicity and amaze professionals with its power," said Jobs. "Apple’s innovation is leading the way in personal computer operating systems once again."

Cool Aqua Aqua retains much of the Mac’s beloved interface features, while bringing even the simplest elements – such as buttons and scroll bars - "fully up to date". Aqua offers a stunning new visual appearance, with luminous and semi-transparent elements such as buttons, scroll bars and windows, and features fluid animation to enhance the user’s experience. Traffic-light-like red, amber and green buttons at the top left of each OS X window will close, minimize or open windows.

Mac OS X has several principal goals. Apple will concentrate on a single-OS strategy, unlike Microsoft’s multiple Windows operating systems. OS X will also feature "state-of-the-art plumbing". As part of this "plumbing", Aqua features enhanced navigation features, which Jobs claimed represents a better implementation of the current Mac Finder. While the current Mac OS "generates a ton of windows, and you get to be the janitor," Jobs said, Mac OS X offers a more-convenient management of open windows.

Jobs demonstrated how Save dialogue panels remain associated with specific windows, no matter how those windows are moved or resized. While users can choose to interact with the OS "just like your old Finder," Jobs said, Aqua will enable users to employ a single window that includes browser-style pop-up lists and a Back button.

In addition to the traditional Icon and List views, a new Browser view will let users save the history of their navigation and return to any point in the sequence. A Preview mode will let them inspect the content of any document, including QuickTime movies. A Shortcuts feature includes buttons that let users select all their documents, applications or favourite places, for example.

Mac OS X's built-in email utility will open and display enclosures automatically. A new font panel will let users preview all their fonts, assemble favourite collections of typefaces, or connect to the Internet to purchase fonts on demand.

Killer graphics Another goal for OS X is to provide "killer graphics". Aqua’s new graphics system features all-new 2D, 3D and multimedia graphics. 2D graphics are performed by Apple’s new "Quartz" graphics system, which is based on the PDF Internet standard and features on-the-fly PDF rendering, anti-aliasing and compositing. 3D graphics are based on OpenGL, the industry’s most-widely supported 3D graphics technology, and multimedia is based on the QuickTime industry standard for digital multimedia.

At the core of Mac OS X is Darwin, Apple’s advanced operating system kernel. Darwin is Linux-like, featuring the same Free BSD Unix support and open-source model. Darwin brings an entirely new foundation to the Mac OS, offering Macintosh users true memory protection for higher reliability, pre-emptive multitasking for smoother operation among multiple applications and fully Internet-standard TCP/IP networking.

What's down, Dock? Mac OS X’s main addition to the desktop metaphor is the "Dock", an interface feature centred at the bottom of the Mac screen that lets users organize everything from current applications and documents to Web sites and streaming video. The Dock can accommodate up to 128 items; windows resize automatically to fit the bottom of the viewing area, and a Magnification feature lets users check the contents. Similarly, users will be able to dramatically resize icons.

Apple has designed Mac OS X to enable a "gentle migration" for its customers and developers from their current installed base of Macintosh operating systems. Mac OS X can run most of the over 13,000 existing Macintosh applications without modification. However, to take full advantage of Mac OS X’s new features, developers must "tune-up" their applications to use "Carbon", the updated version of APIs (Application Program Interfaces) used to program Macintosh computers. Apple expects most of the popular Macintosh applications to be available in "Carbonized" versions this summer.

Developers rally round Aqua Apple announced that more than 100 leading developers have pledged their support for OS X. In a series of rapid-fire, personal-appearance testimonials from third-party developers, Adobe Systems executive vice president Bruce Chizen stated that his company is "committed to having all our key apps at least Carbonized by the time Mac OS X ships’.

Macromedia's Rob Burgess said he was ‘speechless" following the OS X demo, calling it "beautiful". He said that his company was able to port Flash to Mac OS X in a week and a half using just one engineer – "and he wasn’t even that good", Burgess quipped. He promised to deliver all Macromedia's applications to Mac OS X.

Acting general manager of Microsoft Mac business unit, Kevin Browne promised to release Mac OS X versions of Internet Explorer and Outlook Express at the same time OS X is released this summer. Quark's president of desktop development, Richard Jones promised to support the Mac "for the long term". Palm Computing's new Carl Yankowski also offered to support OS X.

When can we have it? The operating system will be in beta testing throughout the second quarter, with final beta this spring. The thoroughly modern new OS will be released in the summer. Finally, a year after this announcement, all Apple machines will be preloaded with the new OS in January 2001.

Additional reporting by MacWeek's Matthew Rothenberg and John Batteiger.

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