Developer Documentation
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The /System Directory

The /System directory contains applications, documents, and resources that are part of the Mac OS X operating system. It is analogous to the System Folder in the Mac OS, with one major exception:

With Mac OS X, the operating system "owns" the /System directory. As part of the upgrade process from one release of the operating system to the next, the files and directories under /System may be overwritten or modified. For this reason, users and developers should not make changes to the /System directory. To protect /System against inadvertent alteration, it and its subdirectories can be altered only by users with root privileges.

The standard directories under /System are these:

Administration

Contains Apple-supported applications that are used mainly by system administrators and network managers.

Applications

Contains Apple-supported applications for users. In it are general-interest applications like TextEdit, Preferences, MailViewer, and PrintManager.

Demos

Contains programs that demonstrate the capabilities of Mac OS X. These aren't full applications and aren't supported by Apple. However, they include games and utilities that users, not just developers, might find interesting.

Developer

Contains Apple-supported applications and files that are used for developing Mac OS X applications.

Applications

Contains Apple-supported programs for application development, such as Project Builder and Interface Builder.

Examples

Contains source code for example programs.

Documentation

Contains Apple-supported documentation of interest to various types of users, on the subjects of:

Administrator

...system administration

Developer

...application development

User

...end-user applications

...

...other topics, for example UNIX manual pages.

Installation

Contains records created during product installation. These records are used by the Installer application to control upgrading and uninstallation of software products.

Library

Contains resource files organized into several directories. Click the link at left for more information.

The /System/Library directory

Library directories organize the resource files used by applications and the operating system. In particular, /System/Library contains system-wide resources, such as standard fonts, sounds, and software frameworks.

Here's a list of the directories that typically appear in /System/Library. [[ Descriptions forthcoming ]]

Adaptors

Addresses

ColorPickers

Colors

Devices

Drivers

Fax

Fonts

Frameworks

Images

People

InputManagers

Java

Keyboards

Mac OS

Models

Preferences

PrinterTypes

PS2Resources

Receipts

Rulebooks

Services

Sounds