Chief executive Steve Jobs is expected to offer new details about Apple's forthcoming operating system, the OS X, when he kicks off Apple's annual developer forum Monday.

But industry watchers aren't expecting Apple to unveil any shiny new models at the San Jose, Calif., conference. "The real concern will be on Mac OS X," said analyst David Bailey of Gerard Klauer Mattison. "It's a very important announcement for Apple, (but) it may not have the cachet of hardware." Apple has promised more details on its new operating system, which may go from the developer preview to beta stage. The company will offer its programming faithful updates on all of its favorite code words: Darwin, Aqua, Carbon and Cocoa, among others. Darwin is the open-source core of OS X, which Apple has made publicly available. That core sits underneath the proprietary Aqua, Apple's fluid new animated interface. Developers will also learn more about Apple's two new development environments. Carbon allows programmers to revamp existing programs to take advantage of OS X's new features, while Cocoa promises an advanced object-oriented environment to develop new programs. Although Apple was rumored to be introducing its multi-processor PowerMacs at this year's event, speculation on that has waned. At last year's conference, Apple unveiled two PowerBook notebook computers. The year before, it first announced OS X.