What is Mac OS X DP4?

Mac OS X DP4 is the fourth “Developer Preview” release of Mac OS X (pronounced “ten”, not “ex”), Apple’s upcoming next generation operating system. See the previous three articles in this series for more information:

Mac OS X DP4 was released on May 15th at Apple’s Worldwide Developer Conference. It is the second developer release to include theAquauser interface. As usual, I’ll begin this article with an exploration of some of the core technologies in DP4 before moving on to the (increasingly depressing) gooey bits. (Note that some of the technical features covered in this article have been in Mac OS X since earlier releases but were not included in previous articles due to a lack of documentation and/or space and time constraints.) The later discussion of the GUI and user experience, will focus on new features of DP4 and the differences between DP4 and earlier releases.

NOTE WELL:This article deals with Mac OS X Developer Preview 4,NOTMac OS X. Mac OS X DP4 is a work in progress, not a finished product. You will never find Mac OS X DP4 on a store shelf. It will never come pre-installed on your computer. Unless you are a developer, you will never use it at all. Any and all features present in DP4 are subject to change before release.

The diagrams in this article are all taken from Apple’s excellentdeveloper documentationand are copyright © 2000 Apple Computer, Inc.

Bundles Revisited

Mac OS X Bundles were first covered inmy DP2 reviewand were revisited inthe DP3 article. Briefly, a bundle is a directory in the file system that stores executable code and resources related to that code. Bundles are designed to encapsulate related software resources in a way that facilitates installation, localization, and cross-platform distribution. (Note that Bundles may also contain other Bundles.) See the Apple’s documentation onthe benefits of Bundles(as quoted in my previous article) for more information.