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.
"This is the year Mac OS X becomes a reality for both developers and customers," Apple said on its Web site for the conference.
Bailey said it is critical for Apple to keep improving its user interface and connection to the Internet.
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.
"We don't expect any significant hardware announcements," Bailey said.
Business appears to be on track for Apple heading into the conference.
Morgan Stanley Dean Witter analyst Gillian Munson said this week that second-quarter sales should be flat, despite what is traditionally a slower buying season. In a research note, Munson said high-end PowerMac sales should be up slightly, while consumer-oriented models are slowing somewhat.
"This is built into our model but should be watched," she said.
The developer conference runs through Friday.