System Folder

The System Folder is a folder which acts as a centralized repository for items related to the Macintosh operating system (Mac OS).

A newer version of the directory exists in Mac OS X (now macOS), named System (without "folder" at the end of the name). While Copland was on the drawing board, a proposed name for it was Mac OS Folder.

Classic Mac OS
A System Folder that comes factory installed on a new Macintosh computer may be limited to supporting that specific model (or closely related models) and may not necessarily be interchangeable with others. System Software upgrades sold at retail introduced the concept of "Universal System Folder" installation, in which a single System Folder can contain all the resources needed to universally support all compatible models at the time of the upgrade's release.

In Macintosh computers with multiple drives or multiple System Folders, a specific folder can be "blessed" so that it will be selected for the computer to boot from upon startup.

System 1
From System 1 until the last version of System 6, there was virtually no structural order within the System Folder. Everything (with few exceptions) was placed loose within the root level of the folder. The System Folder of System 1 started out with only 6 items:


 * Finder
 * System
 * Imagewriter
 * Clipboard File
 * Scrapbook File
 * Note Pad File

System 7
In System 7, some long-awaited organization finally took place. The following folders were created inside the System Folder:


 * Apple Menu Items folder (which includes desk accessories previously incorporated into the System file.
 * Control Panels folder
 * Extensions folder
 * Preferences folder
 * PrintMonitor Documents
 * Startup Items

System 7.1
System 7.1 added the Fonts folder into the System Folder, making the Font/DA Mover obsolete.

System 7.5
System 7.5 added yet more folders into the System Folder:


 * Control Panels (disabled) folder
 * Control Strip Modules folder
 * Extensions (disabled) folder
 * Launcher Items folder
 * Shutdown Items folder
 * Speakable Items folder

Mac OS 8
In Mac OS 8, the Contextual Menu Items folder, along with contextual menus, debuted on the Mac OS.

Mac OS 8.5
The following were added by Mac OS 8.5:


 * Appearance folder
 * Favorites folder
 * Help folder
 * Internet Search Sites folder
 * Scripts folder

Mac OS 9
Mac OS 9 added these folders into the System Folder:


 * Language & Region Support folder
 * Scripting Additions folder
 * Text Encodings folder

Mac OS X
Mac OS X reorganized the System folder, UNIX-style, and by defauly blocked users without administrator privileges from modifying it the way they could under the classic Mac OS. The folder was also renamed System instead of System Folder. Critical files are stored inside a Library folder inside the System folder.