A Manager was any of a set of specialized components of the Mac OS

Mac OS

Mac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The Macintosh user experience is credited with popularizing the graphical user interface...

 operating system

Operating system

An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

, including those that comprised the Macintosh Toolbox

Macintosh Toolbox

The Macintosh Toolbox is a set of application programming interfaces with a particular access mechanism. They implement many of the high-level features of the Mac OS. The Toolbox consists of a number of "managers," software components such as QuickDraw, responsible for drawing onscreen graphics,...

. Each of these Managers was responsible for handling system call

System call

In computing, a system call is how a program requests a service from an operating system's kernel. This may include hardware related services , creating and executing new processes, and communicating with integral kernel services...

s from applications

Application software

Application software, also known as an application or an "app", is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with...

 running on the Macintosh, and could be built into the ROM

Old World ROM

Old World ROM Macintosh computers are the Macintosh models that use a Macintosh Toolbox ROM chip, usually in a socket . All Macs prior to the iMac use Old World ROM, while the iMac and all subsequent models until the introduction of the Intel-based EFI Models are New World ROM machines...

 or be loaded into RAM by the system.

Many of these Managers and their functions have been ported to or re-implemented in the Carbon

Carbon (API)

Carbon is one of Apple Inc.'s procedural application programming interfaces for the Macintosh operating system. It provides C programming language access to Macintosh system services...

 application framework

Application framework

In computer programming, an application framework consists of a software framework used by software developers to implement the standard structure of an application for a specific development environment ....

s. Some of the Managers included in various versions of the Mac OS include:

• Code Fragment Manager (CFM)
• Component Manager
  Component Manager
  In Apple Macintosh computer programming, Component Manager was one of many approaches to sharing code that originated on the pre-PowerPC Macintosh. It was originally introduced as part of QuickTime, which remained the part of Mac OS that used it most heavily....
  
  
• Data Access Manager
  Data Access Manager
  The Data Access Manager was a database access API for the Mac OS, introduced in 1991 as an extension to System 7. Similar in concept to ODBC, DAM saw little use and was eventually dropped in the late 1990s. Only a handful of products ever used it, although it was used for some extremely impressive...
  
  
• File Manager
• Mixed-Mode Manager
• Resource Manager
• Scrap Manager
• Sound Manager
  Sound Manager
  The Sound Manager is a part of the classic Apple Macintosh operating system, in Mac OS. It is used to control the production and manipulation of sounds on Macintosh computers. The Sound Manager is also used by other parts of the Macintosh system software that produce sounds, such as the Speech...
  
  
• Speech Manager
  Speech Manager
  The Speech Manager, in the classic Mac OS, is a part of the operating system used to convert text into sound data to play through a sound output device such as a speaker. The Speech Manager's interaction with the Sound Manager is transparent to a software application.-External links:*...
  
  
• Window Manager