Apple Computer Inc. is planning to put the user at the center of its next major release of Mac OS X.

According to sources, that's the umbrella term the Cupertino, Calif., Mac maker is applying to an arsenal of innovative new features in store for Mac OS X 10.3, a k a "Panther," reportedly due to ship in September. They said User at the Center features will make it simpler for individual users to personalize their computing experience and to move seamlessly among Macs and other devices. And as a marketing strategy, Panther's User at the Center capabilities are intended to challenge user-centric capabilities of Microsoft Corp.'s Windows XP as well as its forthcoming "Longhorn" client.

Features of the OS reportedly won't be frozen until May, but a variety of enhancements are in the running that will encourage pervasive, mobile computing. For example, one proposed feature will let users take home directories they've saved on peripherals and networks and use them for file access or securely log into a Mac running Panther. Sources said the feature will let users synchronize their home directories with mobile devices or log onto a system via Apple's .Mac service. Another candidate feature will let users log out of OS X and then log back in as another user, without having to close open applications. This capability resembles the "Fast User Switching" feature of Windows XP.