If you're curious about the contents of the Extensions folder, this document provides a brief description of each extension. You can use these descriptions to help determine which extensions you may need and which ones you may not need. The features in this document are specific to the OS 7.6. However, They provide basic insight into the contents of Extension Folder for other versions of Operating Systems, in general.

What is an extension?
An extension is a small file that changes how your computer operates. Unlike a control panel, you typically do not have any direct interaction with an extension. An extension makes the appropriate changes when you start your computer and remains active until you shut down your computer.
Depending on the type of computer you have, the contents of your Extensions folder may vary. You might also have extensions that were added by third-party applications. You can use the Extensions Manager control panel to turn off any extension you don't need. Extensions with the letters "lib" in them are typically code libraries that may be used by multiple applications or system components. Turning off libraries may have unexpected effects. In general, you shouldn't turn off any extensions unless you know for certain what they're used for.

EM Extension
Used by the Extensions Manager control panel.

9500 Guide Additions
Adds step-by-step instructions for using features specific to the Power Macintosh 9500 to the onscreen help provided in Macintosh Guide. You can access Macintosh Guide from the Guide (question mark) menu when the Finder is active.

A/ROSE
Allows communication between your computer's main logic board and NuBus cards that run the Apple Real-Time Operating System. Examples of such NuBus cards include the Apple Token Ring 4.16 NB card and the Apple Serial NB card.

About Apple Guide
Provides information about how to use Apple's onscreen help system. You can access About Apple Guide from the Guide (question mark) menu when the Finder is active.

Apple Built-In Ethernet and Apple Ethernet NB
Used by Open Transport to allow access to the built-in Ethernet port on your computer.

AppleCD Audio Player Guide
Provides step-by-step instructions for using the AppleCD Audio Player. You can access the AppleCD Audio Player Guide from the Guide (question mark) menu, after you install and open AppleCD Audio Player.

Apple CD-ROM
Enables your computer to use an Apple CD-ROM drive.

Apple Color Printer
Enables your computer to print documents on an Apple Color Printer.

Apple Color SW Pro CMM
Contains color-matching information used by ColorSync 2.0 to maintain consistent color between documents.

Apple Guide
Enables your computer to use Apple's onscreen help system.

Apple Photo Access
Part of the CD-ROM software for viewing Kodak PhotoCDs.

AppleScriptLib
Provides native support for AppleScript on PowerPC-based computers.

AppleScript
Enables automation of repetitive tasks in applications that support it. Some applications, such as Apple onscreen help, require AppleScript to work.

AppleShare
Gives you access to shared disks on the network.

AppleTalk ImageWriter
Enables your computer to print documents on a networked ImageWriter II.

AppleVision Guide Additions
Adds step-by-step instructions to Mac OS Guide about how to use AppleVision displays with your computer. You can access Mac OS Guide from the Guide (question mark) menu when the Finder is active.

Assistant Toolbox
This is the base extension for AutoRemounter. AutoRemounter works on portable computers and allows file synchronization, battery management, and easy mobile computing. It also provides support for a persistent RAM disk and deferred printing. This extension may conflict with the LaserWriter Select 310 printer software to block printing. A solution is to turn off background printing in the Chooser.

Audio CD Access
Lets you play audio CDs on your internal or external CD-ROM drive. Requires the AppleCD Audio Player or equivalent application to control the audio CD.

AV Guide Additions
Adds step-by-step instructions to Mac OS Guide about how to use AV monitors with your computer. You can access Mac OS Guide from the Guide (question mark) menu when the Finder is active.

AV Setup
Used to control AppleVision displays.

Caps Lock
Provides a visual indication of the state of the Caps Lock key on a portable computer. When Caps Lock is turned on, an "up" arrow appears in the menu bar next to the Guide (question mark) menu. (Not needed on Macintosh PowerBook 500 series computers.)

Clipping Extension
Lets you use the drag-and-drop feature to create clipping files on your desktop.

Color Picker
Presents a standard interface for color selection. Applications can use this tool to let you choose colors.

Color SW 2000 Series CMM
Color-matching information used by ColorSync to maintain consistent color between documents printed on a Color StyleWriter 2000 series printer and other color devices.

Color SW 2400
Enables your computer to print documents on a Color StyleWriter 2200 or Color StyleWriter 2400.

Color SW Pro
Enables your computer to print documents on a Color StyleWriter Pro.

ColorSync
Matches colors on your display with the closest matching colors on your printers, scanners, and other devices.

Desktop Printer Extension, Desktop Printer Spooler, Desktop PrintMonitor
All three of these files are necessary for the desktop printing feature to work. (With desktop printing, you can print documents by dragging their icons to printer icons.)

Energy Saver Guide Additions
Adds step-by-step instructions for using Energy Saver to the onscreen help provided in Mac OS Guide. You can access Mac OS Guide from the Guide (question mark) menu when the Finder is active.

EtherTalk Phase 2
Lets you connect your computer to an Ethernet network.

File Sharing Extension
Enables your computer to share files and folders with other computers on your network.

Find File Extension
Lets you search for files and view the results in a single window. If you turn off this extension and choose Find from the File menu, you'll get the System 7.1 Find dialog box instead of the Find File window.

Finder Help
Provides Balloon Help support for the Finder.

Finder Scripting Extension
Allows you to use AppleScript to automate tasks in the Finder.

Foreign File Access
Enables your computer to work with CD-ROM discs whose contents don't use the standard Mac OS file system (for example, ISO 9660 or High Sierra formats).

Global Guide Files folder
Contains files used by the onscreen help system. Some of these files may be used to provide help more than one application.

Graphics Accelerator
Provides video acceleration for the PCI video card.

High Sierra File Access
Part of the CD-ROM software that lets you view CDs with High Sierra file systems.

IIci/IIsi Monitors
Describes the capabilities of the built-in video card for the Macintosh IIci and IIsi. If you remove this file, your computer can still use the video card and you can still select the number of colors displayed on your monitor, but monitor options (such as gamma settings) may not be available.

ImageWriter
Enables your computer to print documents on an ImageWriter or ImageWriter II connected to a serial port.

ImageWriter LQ
Enables your computer to print documents on an ImageWriter LQ connected to a serial port.

ISO 9660 File Access
Part of the CD-ROM software that lets you view CDs with ISO 9660 file systems.

LaserWriter 300
Enables your computer to print documents on a Personal LaserWriter 300, LaserWriter Select 300, or a Personal LaserWriter LS.

LaserWriter 8 (version 8.x)
A PostScript level II print driver that enables your computer to print documents on a PostScript printer connected to an AppleTalk network.

LaserWriter IISC
Enables your computer to print documents on a LaserWriter IISC connected to a SCSI port. Replaced by Personal LaserWriter SC.

LW Select 310
Enables your computer to print documents on a LaserWriter Select 310.

MacinTalk 3
Lets your computer read text documents in human-like voices.

Mac OS Guide
Contains step-by-step instructions for working in the Finder. You access Mac OS Guide from the Guide (question mark) menu when the Finder is active.

Monitors & Sound Guide Additions
Adds step-by-step instructions for using the Monitors & Sound control panel to Mac OS Guide. You access Mac OS Guide from the Guide (question mark) menu when the Finder is active.

My Speech Macros
Supports the Speech Macro Editor.

Network Extension
Lets you set Personal File Sharing from the Finder.

OpenDoc Libraries folder
Contains code libraries and other files that enable OpenDoc technology.

ObjectSupportLib
A library developers use to support AppleScript on computers with PowerPC microprocessors.

Open Transport Guide Additions
Adds step-by-step instructions for using Open Transport networking software to Mac OS Guide. You access Mac OS Guide from the Guide (question mark) menu when the Finder is active.

Open Tpt AppleTalk Library
Used by Open Transport for the AppleTalk communication protocol.

Open Tpt Internet Library
Used by Open Transport for the TCP/IP communication protocol.

Open Transport Library
Used by Open Transport.

OpenTptAppleTalkLib
Used by Open Transport for AppleTalk communication protocol.

OpenTptInternetLib
Used by Open Transport for the TCP/IP communication protocol.

OpenTransportLib
Used by Open Transport.

PB 500 Upgrade Guide Additions
Adds step-by-step instructions for using features specific to the PowerBook 500 to Mac OS Guide. You can access Mac OS Guide from the Guide (question mark) menu when the Finder is active.

PB 190 Upgrade Guide Additions
Adds step-by-step instructions for using features specific to the PowerBook 190 to Mac OS Guide. You can access Mac OS Guide from the Guide (question mark) menu when the Finder is active.

PB 2300 Upgrade Guide Additions
Adds step-by-step instructions for using features specific to the PowerBook 2300 to Mac OS Guide. You can access Mac OS Guide from the Guide (question mark) menu when the Finder is active.

PB 5300 Upgrade Guide Additions
Adds step-by-step instructions for using features specific to the PowerBook 5300 to Mac OS Guide. You can access Mac OS Guide from the Guide (question mark) menu when the Finder is active.

Personal LaserWriter SC
Enables your computer to print documents on a Personal LaserWriter SC or a LaserWriter IISC.

Portable StyleWriter
Enables your computer to print documents on a Portable StyleWriter.

PowerBook Guide Additions
Adds PowerBook-specific topics to Mac OS Guide. You can access Mac OS Guide from the Guide (question mark) menu when the Finder is active.

PowerBook Monitors Extension
Describes the PowerBook built-in display. If you remove this file, your computer can still use the PowerBook video card and you can still select the number of colors your screen can display, but certain options (such as gamma settings) may not be available.

PowerPC Monitors Extension
Supports the AudioVision 14 monitor.

Printer Descriptions
Contains descriptions for all printers that use the LaserWriter 8 printer software.

Printer Share
Provides the ability to share non-network printers (for example, the StyleWriter II) across a network.

PrintingLib
Used by the desktop printing software.

PrintMonitor
Controls the printing process when background printing is activated.

Quadra AV Monitors Extension
Describes the capabilities of the built-in video card for the Macintosh Quadra and Centris AV computers. If you remove this file, your computer can still use the video card and you can still select the number of colors displayed on your monitor, but monitor options (such as gamma settings) may not be available.

Quadra Monitors Extension
Describes the capabilities of the built-in video card for the Macintosh Quadra and Macintosh Centris computers. If you remove this file, your computer can still use the video card and you can still select the number of colors displayed on your monitor, but monitor options (such as gamma settings) may not be available.

QuickTime
Provides built-in multimedia support for applications.

QuickTime PowerPlug
Provides native support of QuickTime for PowerPC-based computers when used in combination with QuickTime 2.0. This extension must be used in addition to QuickTime 2.0.

QuickTime Musical Instruments
Supports 30 Roland Standard MIDI sound samples that can be accessed by QuickTime applications with no additional MIDI equipment.

Scripting Additions
Extends the AppleScript language with special features, such as finding the date or time of day. With scripting additions installed, AppleScript acts as if these features are part of the language. Scripting additions are required only when a script uses them.

Serial (Built-In)
Used by Open Transport to allow access to the built-in serial port on your computer.

Shared Library Manager
Provides native support for Open Transport.

Shortcuts
Explains common keyboard equivalents and other shortcuts to use in the Finder. You can access Shortcuts in the Guide (question mark) menu when the Finder is active.

SimpleText Guide
Provides step-by-step instructions for using SimpleText. You can access the SimpleText Guide from the Guide (question mark) menu, after you open SimpleText.

Speech Guide Additions
Adds step-by-step instructions for using speech recognition to the onscreen help provided in Mac OS Guide. You can access Mac OS Guide from the Guide (question mark) menu when the Finder is active.

SOMobjects for Mac OS
Used by OpenDoc.

Speech Manager
Provides text-to-speech capabilities.

SR Monitor
Used to monitor and interpret speech.

Startup Tuner
Ensures correctly starting up from the disk selected in the Startup Disk control panel.

StyleWriter II
Enables your computer to print documents on a StyleWriter II. Replaced by StyleWriter 1200.

StyleWriter 1200
Enables your computer to print documents on a StyleWriter, StyleWriter II, or StyleWriter 1200.

SystemAV
Used for audio-video input.

System Speech Rules
Supports voices and speech dialects.

TokenTalk Phase 2
Used by the Apple Token Ring card.

TokenTalk Prep
Supports TokenTalk Phase II.

Tutorial Items
Provides instructions for learning basic skills on your computer. You can access the tutorial from the Guide (question mark) menu when the Finder is active.

Video Startup
Used by the Apple Video Player.

Voices folder
Includes voices your computer can use when reading text or speaking alert messages.

WorldScript Power Adapter
Supports language kit software on PowerPC-based computers. However, computers that use the Roman alphabet (English and French, for example), can still take advantage of performance and stability enhancements provided by the WorldScript Power Adapter.