The public beta for Apple's Mac OS X will be rolled out on September 13 at the Apple Expo in Paris, company chief executive officer Steve Jobs said in a keynote speech here Tuesday in which he addressed the OS delay with humor. Apple had said that OS X would be out during the summer, so Jobs in his keynote address here at the Seybold publishing conference posed the question "What's summer?" He then looked it up in Webster's dictionary, announcing that summer - in the Northern Hemisphere anyway - officially begins with the June solstice and ends with the September equinox due to fall on September 23. By that measure, the OS X beta will be out in Apple's pledged time frame (though the company had promised a "shrink wrapped" version would be out by the middle of this year). "We're very, very strong on this," Jobs said about the public beta, spending part of his keynote address showing off some of the new operating systems' features. He described OS X in layers, with Darwin forming the core operating system kernel, which Jobs said is fully open source. On top of Darwin are three pieces - Quartz 2D graphics capabilities, OpenGL for 3D graphics and Apple's QuickTime for multimedia. Above those components are a trio of APIs (application programming interfaces) - Classic, which allows users to run existing Mac applications "as is;" Carbon, which enables the use of all the new OS X features; and Cocoa, which is derived from the object-oriented OpenStep operating system. Apple acquired OpenStep when it purchased Next Software in late 1996 - Jobs founded Next after leaving Apple. Unifying the three APIs is Apple's Aqua user interface. Jobs said that developers "from Adobe to Microsoft" are working to "carbonize their applications." Features in the public beta will include full support for Java2 and full SMP (symmetric multiprocessing), Jobs said. Another feature OS X offers is more rapid wake-up times for Apple PowerBook notebooks. Currently, waking up a PowerBook from sleep mode running OS 9 can take anything from eight to 22 seconds, with OS X only taking one second, Jobs claimed. However, the demonstration of such a capability, which he tried twice, failed both times. Mac OS X will also include an MP3 player that users can run on their desktop if they like. Ease of use is the new operating system's main raison d'etre, Jobs said. "With OS X, we're cleaning up the system in terms of simplicity," he added. The new OS will include a new finder, which after attracting criticism from Apple users, will now do everything the current finder in OS 9 can do, according to Jobs. Some OS X testers had also complained about Apple's all-colour Aqua interface, Jobs said. "Too much colour was intruding on their content," he added. So, users will have the ability to switch to "graphite" mode so that they will be able to remove all the colour from user interfaces, should they wish to do so. OS X features that drew plenty of applause from the Seybold audience were the addition of "sheets" as a simpler way of naming and managing files. Users can save files in favorite or recent places, as well as anywhere they choose in the entire file system, Jobs said. Microsoft is working on a "carbonized version" of its Web browser, Internet Explorer 5.5, which will ship with OS X, Jobs said. The browser will include Macromedia's Shockwave and Flash software already built into it, he added. Jobs also highlighted the Dock feature of OS X, describing it as "a wonderful unified place for all the applications you have running and miniaturized windows." Users can also save their URLs in the dock, he added. Macromedia executives came on stage to show the company's DreamWeaver Web site creation sites running on OS X. The executives used the Web site, where anyone can set up headlines and content to set themselves up as a US presidential candidate. They put Jobs down as a candidate, to much applause and laughter from the audience. When he wasn't talking about OS X, Jobs was reiterating announcements he made six weeks ago at Macworld, talking up Apple's G4 chips and the company's full hardware range. The Apple CEO also took the opportunity to run a number of videos of Apple advertisements, including those for the new iMac colours and the Power Mac G4 Cubes. He offered a shootout performance demonstration with a 500MHz G4-powered Power Mac running OS 9 taking on a PC powered by a 1GHz Intel Pentium III processor and running Windows 2000 Professional edition. In the demonstration, both computers ran a 70MB graphics file, an advertisement for the movie "Inspector Gadget." In the test, the Power Mac took 108 seconds to run the graphics file from start to finish, while the Intel-based machine took 124 seconds. Chanting the mantra "Two brains are better than one," Jobs then ran the same demonstration using two 500MHz G4 chips in the Power Mac against the same 1GHz Intel machine. That time, the results were Power Mac, 61 seconds, versus the Intel machine's 124 seconds. Jobs told the Seybold audience to expect more dual processor announcements from Apple in the future. "Dual processors are really a big deal; they're getting us ahead of anyone in the PC business." Bruce Chizen, Adobe's president, joined Jobs onstage to give the first major public demonstration of the company's publishing software PhotoShop 6 since its Monday release running on Apple's hardware.