from Wikipedia, the free encyclopedia
developer Apple Inc.
programmed in C , C ++ , Objective-C , Swift
License (s) EULA ; APSL , BSD , GPL , among others
First publ. March 24, 2001
Current  version 10.15.5 (additional update) from June 1, 2020
(88 days ago)
Basic system Darwin
Kernel XNU ( hybrid kernel )
ancestry Unix → BSD
↳ Rhapsody
↳ Mac OS X (10.0-10.7)
OS X (10.8-10.11)
macOS (10.12+)
Architecture (s) x64 (≥ 10.6) ,
ARM (≥ 11.0) ,
x86 (10.4.4-10.7) ,
PowerPC (≤ 10.5)
timeline Mac OS X ...
Public Beta ("Kodiak", 2000)
10.0 ("Cheetah", 2001)
10.1 ("Puma", 2001)
10.2 ("Jaguar", 2002)
Panther 10.3 (2003)
Tiger 10.4 (2005)
Leopard 10.5 ( 2007)
Snow Leopard 10.6 (2009)
Lion 10.7 (2011)
Mountain Lion 10.8 (2012)
Mavericks 10.9 (2013)
Yosemite 10.10 (2014)
El Capitan 10.11 (2015)
Sierra 10.12 (2016)
High Sierra 10.13 (2017 )
Mojave 10.14 (2018)
Catalina 10.15 (2019)
Big Sur 11.0 (2020)
compatibility UNIX 03 ( POSIX etc.), FreeBSD , Mac OS Classic ( historical )
Languages) multilingual ( see below ),
u. a. German

The operating system macOS , formerly Mac OS X and OS X , is the operating system of the Californian hardware and software company Apple for laptop and desktop computers of the Mac series. It offers an object-oriented desktop environment as well as Unix- typical, UNIX-03 -certified interfaces and is the commercially most successful Unix for personal computers . With it, Apple replaced its classic Mac operating system, Mac OS . It also became the foundation for further Apple developments such as the iPod and iPhone . For this is Darwin with its hybrid kernel XNU the common base.

A server version of the operating system is offered separately and was delivered preinstalled on Mac server models.

The current version is macOS Catalina 10.15; It is expected to be replaced by macOS Big Sur , which will have version number 11.0, in October 2020 ; it can be tested in advance.


In detail, macOS is a proprietary operating system based on the Unix-like basic Darwin operating system , the source code of which is published under the free Apple Public Source License . The development of macOS and Darwin goes back to NeXTStep , which is a derivative of the Berkeley Software Distribution . Today's Darwin is essentially a derivative of FreeBSD , supplemented by OpenBSD, NetBSD and own developments. From version Leopard 10.5 , macOS (but not Darwin itself) is certified as UNIX 03 . Despite elementary technical differences to the classic Mac OS, which is not unix-like , macOS is historically the youngest member of the Mac operating system family , which was introduced for in-house Mac computers from 1984 .

The macOS derivative iOS runs on the iPhone , iPod touch and iPad . With iPadOS, an iOS derivative was developed for the iPad, which improves the cooperation with macOS. The Apple TV software began as a macOS derivative and is now tvOS , an iOS derivative. Also watchOS for the Apple Watch is an iOS derivative. They all rely on Darwin too. Likewise the software of the HomePod , which is operated by voice.


Steve Jobs had to leave Apple, which he co-founded, in 1985 at the urging of management. He then founded NeXT, where he worked on both hardware and software with a few trusted Apple developers who left Apple with him. The core of the effort was the NeXTstation and the NeXTStep operating system. But while the NeXT operating system was highly praised by experts, the hoped-for hardware sales of the NeXTstation did not materialize. NeXT had no choice but to stop hardware production in 1993 and offer the operating system for external computer architectures as well. Together with Sun, the object-oriented NeXTstep programming interface was further developed as a cross-platform framework for OpenStep from 1995 . Accordingly, the newly implemented operating system from Version 4 was called OPENSTEP .

At Apple, on the other hand, the hardware sold relatively well, but the original Macintosh operating system was considered technically obsolete and not sustainable. Apple therefore made some efforts and attempts to develop a new operating system that should be largely compatible with the original Macintosh operating system. However, since there was still no modern successor in sight at the end of 1996 and at the same time hardware sales continued to decline, Apple finally endeavored to adopt an existing operating system.

Ultimately, at the end of 1996, Apple bought NeXT, including the OPENSTEP operating system. The NeXT employees were integrated into their own company, and Steve Jobs took over the management of Apple again in 1997.

Immediately after the takeover OPEN STEP was the project Rhapsody modernized and the Apple then used in the Macintosh PowerPC - Architecture ported. First, Rhapsody was supposed to completely replace the original Macintosh operating system, for which software providers would have had to completely rewrite their applications - which they rejected. Apple responded by further developing Rhapsody into "Mac OS X". The switch from the original Macintosh modular system to the new Mac OS X was made easier for developers with the introduction of Carbon , and the Classic environment retained full compatibility with the previous operating system for users .

When "Mac OS X" was announced in 1998, the X was supposed to be the Roman  ten, the successor to the classic Mac OS , the last major version of which was number 9. On the other hand, it was supposed to highlight the unix-like origins of the new generation of operating systems, which in English was not arbitrarily advertised as “next generation”.

The operating system itself, officially called "OS X", was marketed without a "Mac" in its name from 2011 and officially called " OS X Mountain Lion " from 2012 onwards. On June 13, 2016, during the keynote at WWDC, it was announced that version 10.12 of the operating system would be released in autumn as " macOS Sierra " and that the product line would be renamed from "OS X" to "macOS". Apple explained that this is done to match the naming of the other Apple platforms (iOS, tvOS, watchOS).

At Apple, the individual main versions were initially given internal code names. The first public beta was named after the Kodiak bear . The cheetah was the namesake of the first major version, Mac OS X 10.0, and the second major version was also named after a large small cat , the puma . Version 10.2 was codenamed after the jaguar and was the first major version to be named after a big cat . With Mac OS X Panther 10.3 (several types of cats and one genus are referred to as Panther ), the internal code name became part of the product name. From then on, all major versions were named after (colloquial) terms for big cats. When the number of major versions exceeded the number of actual big cat species, a new scheme was introduced: currently, major versions are named after California's natural landmarks . Starting with the Mavericks surf spot as well as Yosemite National Park and El Capitan , a prominent rock ledge in it. It was followed by the Sierra Nevada and the Mojave Desert , which is partly in California. The island of St. Catalina is currently named after it.


System architecture: OS X is based on Darwin and the Mach-based hybrid kernel XNU.

The architecture is divided into four basic levels:

Usage level
Aqua , the graphical user interface (GUI) that enables the graphical desktop environment .
Application programming level
Programming interfaces (APIs) such as Cocoa (and earlier Carbon ), Java
Deployment level
Core Foundation , Core Services , graphics subsystems ( Quartz with Quartz Compositor , Metal or OpenGL ), Audio / Video ( QuickTime ), PrintCore etc.
Base level / foundation
Darwin , the core operating system with the XNU kernel


Darwin is the basic foundation on which macOS is built. With Darwin and the XNU kernel , macOS has capabilities such as memory protection , preemptive multitasking , multi-user capability, extended memory management and symmetrical multiprocessing ( SMP ). Darwin was the open source license Apple Public Source License asked which freer with version 2.0 as licensed software by the Free Software Foundation was recognized. The kernel called XNU (X is Not Unix) has been completely revised compared to OPENSTEP. While OPENSTEP still used a Mach 2.5, Darwin's kernel is based on the then revised OSF Mach Kernel 3.0 (OSFMK for short). As early as the Rhapsody operating system project , the OSFMK was supplemented with parts of the monolithic FreeBSD kernel and thus implemented as a hybrid kernel . Experience from MkLinux also flowed into the modernization.

In addition, macOS provides a user land, mostly from FreeBSD and NetBSD, which can be accessed via the included Terminal u. a. Terminal emulations can be used. Several Unix shells are preinstalled: Bash ( bash, sh); the Z shell ( zsh, bash, sh); the TENEX C shell ( tcsh, csh, sh), which was set as the Panthers in older versions; the KornShell ( ksh, sh) . Since Catalina 10.15, the Z shell has been preset as the shell. From Panther 10.3 up to and including Mojave 10.14, Bash was the default.

Aqua, Cocoa, Quartz (Extreme)

The fully object-oriented programming interface based on OpenStep has been further developed into Cocoa . With Aqua, a completely new graphical user interface was designed, whose design concept, like the programming interface Cocoa and Quartz with display PDF and the dock , is largely based on NeXTStep developed by NeXT.

The global menu bar , the Finder and QuickTime as well as a few other libraries have been adopted from the classic Mac OS . The original Macintosh toolkit could not be fully integrated into Mac OS X because the functions were not compatible with modern operating system functions such as memory protection and multitasking. Instead, carbon was used to integrate 6,000 of the 8,000 or so functions of the Macintosh modular system, and thus a large part of it, into Mac OS X, which made porting existing applications easier.

The most noticeable change in macOS compared to its predecessors, the classic Mac OS up to version 9 and Rhapsody, which still had the surface of Mac OS 8, is the new surface Aqua ( Latin for water). It should be reminiscent of water droplets through lighting effects such as reflections and cast shadows on various surface elements such as buttons or overlaid menus. The pinstripe look of the window backgrounds and the photo-realism (up to Yosemite) of the icons are also striking .

Another appearance for windows was Brushed Metal up to Tiger 10.4 (2005) . In the Apple Human Interface Guidelines , Apple recommends using this design for programs that represent part of the hardware or a specific device (such as a digital camera or DVD player ). With Leopard 10.5 (2007) the different appearances were optically standardized.

Completely new elements in Aqua compared to older surfaces are so-called sheets (dt. 'Panels') and drawers (dt. 'Drawers'). Sheets are intended to make it clear to a user to which document an opening dialog box belongs: a kind of dialog window that is attached directly to the title bar of the document in question and which thus becomes its inseparable part. Drawers are drawers that can be opened by clicking on the corresponding button on the left or right of the main window and contain elements that are not permanently required for program operation. In the first version of Apple's e-mail program Mail , for example, the folder structure was in a drawer , but in version 2 it became part of the main window.

Another specialty of Aqua is the way the screen content is displayed. Here Apple uses its own technology called Quartz . This representation of two-dimensional elements is based on the Portable Document Format (PDF). The further development of this technique called Quartz Extreme accelerates the display, as each window is located in a 3D space (which appears two-dimensional to the user) and the window content and shape are viewed as a texture and thus no longer only by the main, but by the graphics processor be calculated. Windows can be scaled and transformed in real time without high processor load.


The native programming and application interface for Aqua programs is Cocoa , which is a further development of OpenStep . Cocoa programs are primarily written in the Objective-C and Swift languages. While the development of Objective-C extends beyond that of NeXTStep, the latter is Apple's own new development that was presented in 2014. It should combine the advantages of modern languages, but not replace Objective-C.

Various bridge interfaces , so-called Cocoa Bridges (see also Bridge ), also make it possible to use Cocoa with Ruby, Python and Java . The Java bridge has not been updated since Tiger 10.4 (2005). With AppleScript Studio it is also the possibility of programs in AppleScript to write and expand with Objective-C or other languages.

Apart from Cocoa and the Carbon library , macOS provides a complete Java 5.0 environment, a POSIX and SUS- compliant BSD environment and, with XQuartz, an X11 environment for classic and standard high-level language programming. In addition, the common Unix programming languages ​​(e.g. Perl , PHP , Python , Ruby and Tcl and C ) are made available. Much of the FreeBSD user land can be accessed at will; see # Programs of other operating systems in macOS .


Backward Compatibility

Compatibility problems within Mac OS X were mainly due to the change in the underlying processor architecture from PowerPC (CPUs from IBM and Motorola , 32- and 64-bit) to IA-32 (CPUs from Intel , so-called Intel Macs ) in January 2006 ), shortly after its introduction also and now only available as 64-bit architecture x64 ( Intel 64 ). For programs written for Mac OS X that require a PowerPC processor, the Rosetta emulation is available on Intel Macs up to Snow Leopard 10.6 . Since Lion 10.7 (2011) this is no longer part of the operating system.

Universal applications contain machine code for both architectures and can therefore be executed natively on PowerPC and Intel CPUs. I.a. Xcode supported this technology, but it is no longer relevant for programs that require Mac OS X Lion or later.

On June 22nd, 2020, it was announced at WWDC that another switch, now to Apple's own chips, will take place. This will take another two years. For this there will be Rosetta 2 and Universal Binary  2. This is combined with a renewal of the virtualization technology in macOS. This means that the Apple SoC Macs remain compatible with older software that has not been recompiled. Support for iOS apps will also be available in this context.

A program written with the Macintosh kit for classic System 7 (or older) was not compatible with the newer Mac OS X. Apple therefore published the program library Carbon for the classic Mac OS from version 8 and the new Mac OS X. Carbon is based on a subset of the original Macintosh Toolbox . Developers did not have to port their programs to Cocoa, but could port from the original Macintosh construction kit to carbon. Such “carbonized programs” ( English carbonized applications ) could run natively on both PowerPC operating systems. Carbon only existed as a 32-bit version, its further development was discontinued in 2007, but was part of the operating system until macOS Mojave , version 10.14 from 2018. In 2019, carbon was removed with macOS Catalina (version 10.15), which is a pure 64-bit operating system.

In order to be able to use non-adapted programs (including those that were still written for the 68k processor ) under Mac OS X, the Classic environment was available up to Tiger 10.4 . This was a Mac OS 9 loaded as a runtime environment within Mac OS X, in which such programs can still be used transparently integrated in Mac OS X. From a technical point of view, the Classic environment is therefore a virtual machine for the PowerPC architecture ( G3 , G4 and G5 ); the environment no longer runs on the Intel Macs introduced in 2006. Most of the older software for Mac OS, including those for very old Macs (68k CPUs), could be used this way. The Classic environment ( English Classic Environment ) is an evolution of Blue Box of Rhapsody .

Compatibility within macOS

Since version 10.8, OS X Mountain Lion from 2012, macOS is only available for the 64-bit architecture x64 ( Intel 64 ). 32-bit programs could still be executed, but device drivers also have to be loaded as 64-bit kext with a 64-bit kernel.

Since version 10.15, macOS Catalina from 2019, only 64-bit applications are generally supported. Older 32-bit macOS programs and those that still use the Carbon library can no longer be run.

Other operating systems on Apple computers

On Macs with a PowerPC processor (up to 2006) it was already possible to use other, mostly free operating systems such as FreeBSD or Linux. Apple itself actively supported MkLinux , so that other Linux distributions could also be started easily via the open firmware . The Mac OS X boot loader BootX could also start Linux.

On PowerPC Macs it was also possible with emulators to use x86 operating systems as a guest operating system under a supported PowerPC operating system. So there was B. Connectix (later Microsoft) Virtual PC that could emulate Windows on a Power Macintosh. However, unlike virtualization , emulation is very slow.

With the change from PowerPC to Intel processors in 2006, it became possible to use a large number of x86-based operating systems on Macs. Apple supports this actively with the supplied since Leopard 10.5 Software Boot Camp , with the help of Windows on a separate partition installed and the BIOS-compatible mode start can be. However , Windows is not supported in EFI mode. Using the EFI boot loaders rEFIT and rEFInd, however, it is possible to mitigate some of the resulting restrictions, e.g. B. can be started from partitions that cannot be selected by the EFI startup manager of an Intel Mac. In addition to Windows, x86 Unices can also still be used, e. As Linux and BSD - distributions .

By changing the processor, it is also possible with virtualization software to run almost any other x86 operating system on a Mac under one of the (supported) started operating systems, e.g. B. in a window. Such programs include a. VMware Fusion , Parallels Desktop for Mac and VirtualBox .

Programs from other operating systems in macOS

Homebrew , Fink or MacPorts , for example , supplement macOS with free Unix, BSD or GNU and other programs.

Another way of running Windows applications is the Windows-compatible runtime environment Wine . The advantage here is that a complete operating system does not have to be running; but above all that no additional Windows license is required. Furthermore, several environments for different Windows versions can run at the same time. Especially through the free Darwine and the commercial CrossOver , Wine under macOS was also accessible to laypeople. Another free project is PlayOnMac, a variant of PlayOnLinux ; it offers an easy-to-use graphical interface for setting up software.

Apple's macOS on other computers

Because standard hardware and Intel chips are used in Apple computers in addition to the self-developed motherboard, there are tinkerers and commercial providers who install macOS on computers other than Apple. Here macOS and drivers are modified or kernel extensions are written. Such systems based on both Intel and AMD are referred to as "Hackintosh", while commercially available configurations are sometimes referred to as "Mac clones".

The Apple license terms only allow macOS to be installed on Apple hardware. It has not been clarified whether users and dealers can legally be prohibited from installing and using the operating system on third-party hardware from Apple. Above all, Apple defends itself against commercially available systems that require little technical knowledge from the buyer. Commercial vendors who convert computers from other manufacturers to operate with macOS were forced by Apple to only deliver their devices without macOS. It remained unclear whether simply setting up PCs to operate macOS is illegal if the retailer himself does not install the operating system in violation of the license.

As of Lion 10.7, the operating system is no longer offered on data carriers. Full versions are only sold as OEM versions with Apple computers. Since the versions available in the Mac App Store are only updates, the possibility of using macOS on other computers with a legal license is de facto not independent of the question of whether Apple may prohibit the use of third-party hardware in the license conditions given more.

For computer hobbyists, there are instructions on websites on how macOS can be operated on computers that are not made by Apple. There are no known cases in which this private use was legally prosecuted.

Even at times when Mac OS X was only available for the PowerPC architecture, it was possible to use Mac OS X on third-party hardware. However, there were only a few freely available motherboards on the market that could be equipped with G3 and G4 processors - for example the Pegasos board, the AmigaOne or the Teron. A complete system based on these components was, however, very expensive to purchase and also required a Mac OS X license, which at that time cost around 100 euros. The configuration of a PowerPC-based Hackintosh was therefore more of a gimmick than a lucrative alternative to Apple hardware.

Applications for macOS in other operating systems

Yellow Box , a forerunner of today's Cocoa programming interface (see also Rhapsody ), was specially designed to be usable under different operating systems on different hardware platforms. In 1997, Apple advertised that this OpenStep -compatible framework could be easily integrated into Windows. Even before Mac OS X was released, these options were restricted again.

The GNUstep project makes use of these portability options, which are still available in macOS, and develops a free replica of the macOS frameworks and libraries. With GNUstep, applications developed for macOS can be compiled for Linux , Unix or Windows without major adjustments and then used.

Based on this, Darling is developed, a macOS-compatible runtime environment with which macOS applications can be used under Linux without recompilation.

File systems

Local file systems

Various local file systems are supported by macOS. Preferred is the APFS introduced with High Sierra 2017 , which is intended to replace the still supported HFS + .

With macOS Sierra (10.12) in 2016, support for the original Macintosh file system HFS was completely eliminated .

A partition formatted with APFS or HFS + is provided as the start volume (partition from which the system is booted ). Up to Tiger 10.4, the operating system could be installed on a partition formatted with the Unix file system UFS and started from there. With Leopard (10.5, 2007) this was no longer possible and with Lion (10.7, 2011) the UFS support was completely eliminated.

Other natively supported file systems are: ISO 9660 , FAT12 , FAT16 and FAT32 , exFAT (from 10.6.5), NTFS a (from 10.6), UDF (read only).

Restricted read access to ZFS was possible in Leopard 10.5, but was no longer supported with Snow Leopard 10.6.

aWrite access to NTFS is deactivated by default and can be activated by changing the fstab file.

Network file systems

Natively supported network file systems are AFP , FTP (read-only), NFS , SMB / CIFS and WebDAV .

Supplement file systems

MacFUSE or its successor OSXFUSE is a macOS variant of FUSE . This means that file systems from other platforms can be made available, but you can also develop your own file systems; In theory, any database can be made available in the form of directories and files and attached to the local directory tree - e.g. B. as dynamically generated XML or JSON files. In combination with the "Monitor folder" function integrated in macOS, additional automation options are available on the GUI level.

For example, FUSE can be used to access files on a portable media player, including an iPod, by listing the track names as file names rather than the actual file names. With SSHFS enables files created on another computer ( english remote computers ) to which by a SFTP connection is accessed to be able to treat them like local files. With NTFS-3G it is possible to write to NTFS partitions. Although Mac OS X has provided NTFS read access since Panther 10.3 (2003), the macOS own write access, which is available from Snow Leopard 10.6 (2009), is officially still at an experimental stage and is therefore not activated by default.


Apple's macOS offers the typical Unix network properties through Darwin. This makes it relatively easy to connect multiple Macs to form a cluster . Under the name Bonjour , macOS supports Zeroconf , which enables users to use network connections and services without having to configure them beforehand.

It also includes a Samba server and supports SMB and CIFS including printer shares. The Apple Filing Protocol is also still supported.

In addition to CIFS, printers in the network can also be addressed via AirPrint, Internet Printing Protocol , Line Printer Daemon Protocol and JetDirect .


General information on safety functions

If desired, an automatic user login can take place without a password query. For security-relevant operations, a password is still required - as is usual with BSDs.

So far, macOS has rarely been the target of attacks and is therefore considered relatively safe among users. The factors to which this can be attributed is controversial. Up until 2011 , security experts rated Mac OS X as less secure than Windows Vista for example , because security features such as non-executable memory and Address Space Layout Randomization (ASLR) were missing or incomplete. In Lion 10.7 (2011), Apple fundamentally revised the security architecture. This made it safer than comparable operating systems. Apple closes known security gaps with security updates. Sometimes the length of time between becoming known and closing a security hole is criticized.

In June 2015, a study was published that describes serious security gaps in iOS and OS X that can be used to read passwords and data; The researchers took advantage of the lack of security mechanisms in the communication between apps (Cross-App Resource Access , or Xara for short ) . Appropriately manipulated apps could be placed in both the iOS and Mac App Store . Apple was informed of the problems in October 2015 and asked for a period of six months - as is customary in the industry - for troubleshooting.

User rights

Darwin differentiates between normal users (user), system administrators (admin) and the superuser (root). A normal user is not allowed to make changes to the system or to install software outside of his user folder. Programs started by him are only executed with his user rights. The users of the admin group have further rights, they can make system-wide settings, install software and have write access to various system directories. Deeper changes to the system can only be made after separate authentication . A root user account with permanent superuser privileges is disabled by default.


macOS includes the package-oriented firewall ipfw from FreeBSD , which has remained unused by default since Leopard 10.5 (2007). A program-oriented firewall was also introduced in Leopard, in which it is set which programs are allowed to receive incoming data traffic. A graphical user interface for ipfw must be installed separately (e.g. WaterRoof or Flying Buttress).

Initial tests showed that the additional firewall in Leopard 10.5.0 still allows data to pass even if “block all connections” is selected in the settings. Several of these vulnerabilities have been fixed in version 10.5.1. The wording of the user interface has been adapted to “Only allow necessary services” and the number of services still accessible in this mode has been reduced.

Outgoing connections cannot be further configured with the graphical applications provided by macOS; additional programs such as Little Snitch , GlowWorm or TCPBlock are required for this.

App sandbox

The Sandbox app is a security mechanism introduced with Lion 10.7 in 2011 that is intended to make it more difficult for attackers to exploit security gaps in programs. In addition, each program only receives the absolutely necessary rights so that - if it is hijacked by an attacker - it can cause the least possible damage.

For this purpose, the operating system assigns each program its own area of ​​the hard disk, the so-called " sandbox ". The program cannot access the "sandbox" of external programs or other areas of the system. The open and save dialogs are no longer part of the program, but run in a separate system process called Powerbox, as the program itself no longer has access to documents on the hard drive.

Also, any program that supports sandboxing must have a developer-created list of the permissions it needs. (In total there are about a dozen authorizations for functions such as establishing network connections or taking photos with the built-in webcam.) If a program tries to access a function for which it has not requested authorization, macOS blocks this.

In addition, with XPC, a variant of interprocess communication is used, which makes it easier for developers to outsource individual functions of the program to a process that has its own authorization list (privilege separation) . In a media player , for example, the rendering of video files can be outsourced. An attacker who exploits security gaps in this area can then only obtain the permissions for this rendering process, but not further permissions from the media player.


Gatekeeper is a function introduced in Mountain Lion 10.8 in 2012 that ensures that only signed software can be started on the computer. For this purpose, it is checked whether the software is provided with the signature of a developer registered with Apple. If this is not the case, the operating system refuses to run the software. There are different levels of security. Either only programs that have been downloaded from the “ App Store ” are allowed . Then the standard setting, which stipulates that all programs must have a signature certified by Apple, and finally the "weakest" security setting, in which any software can be installed as before. However, users who have not selected the weakest security setting have the option of starting "unsafe" software via the terminal or via the context menu in the Finder. For the latter, however, you need to log in as an administrator, otherwise the user will be asked for an admin password.

Gatekeeper was already available in Mac OS X Lion from version 10.7.3 and could be activated via the terminal. From version 10.7.5 it is officially part of the operating system.


Until 2010, only nine prototypes of virus- or worm-like malware for Mac OS X were known, but none could spread. This includes the first computer worm published on February 13, 2006 in the forum of a US rumor site , which, however, has to be executed deliberately by the user, for Tiger 10.4 - at that time only for PowerPC. Virus scanners for macOS are mainly used to prevent viruses written for other operating systems from being passed through.

Of several known Trojan Horses for Mac OS X, only two were considered generally significant and significantly dangerous until 2010. They can install themselves in the event of careless user behavior, for example hidden in illegal downloads or as an allegedly missing codec on porn sites. The malware for Mac OS X that was most widespread at the time was active in May and June 2011 under the name MAC Defender and disguised itself as an antivirus program. In response, Apple built a daily updated list of malware definitions in Mac OS X. Since February 2012, several variants of the so-called "Flashback" malware have spread to OS X via prepared websites through holes in Java. The maximum number of affected systems was estimated at 600,000. Apple closed the security gap in April 2012 with a Java update and made a program available that can be used to remove the malware from affected computers. Users of older systems can only switch off the Java plug-in, as no updates for Mac OS X older than Leopard 10.5 (2007) were offered. In the Mozilla Firefox browser , Java has been deactivated by default for these Mac OS X versions.

Versions and variants

Major versions

Mac OS X Server 1.0

The first operating system to be named "Mac OS X" was Mac OS X Server 1.0 (1999). It was practically a Rhapsody and is therefore technically not part of this operating system line, but is listed here for the sake of completeness. Like Rhapsody, it lacked compatibility with the original Macintosh operating system Mac OS (“Classic”), which was later compensated for by the development of the Carbon programming interface . The last version was Mac OS X Server 1.2 v3 (2000, internal Rhapsody 5.6). The never officially released Rhapsody 1.0 (internal Rhapsody 5.2) and Mac OS X Server 1.0 (internal Rhapsody 5.3) form the starting point for the development of Mac OS X 10.0.

While Mac OS X Server 1.0 was optionally pre-installed for the server variants of the Power Mac G4 line, the classic Mac OS initially remained the desktop operating system for Macs.

Mac OS X 10.0

Mac OS X Public Beta , codenamed "Kodiak":
Starting September 13, 2000, Apple released a beta version of Mac OS X and sold it for $ 29.95. This release and the previously released to developers Developer Previews enabled early adopters an insight into the upcoming operating system, offering software developers the opportunity to own programs for this system to develop, so that they in turn programs for the final release version of Mac OS X 10.0 release promptly could.

Mac OS X 10.0 , codenamed “Cheetah”:
The first release version of Mac OS X appeared on March 24, 2001 and in many ways was not yet fully developed. It was very slow ( to the point of uselessness on older G3 systems), but was praised for its high stability at such an early stage. 10.0.4 was the last release (June 22, 2001).

Mac OS X Server 10.0 :
Mac OS X Server 10.0 was released on May 21, 2001 - almost two months after Mac OS X 10.0. The operating system is essentially exactly the same as the desktop version, but also offers extensive server software and graphical auxiliary programs that make configuration easier.

Mac OS X 10.1 ("Puma")

Mac OS X 10.1 Desktop Edition:
Mac OS X 10.1 was released on September 25, 2001. It was provided as a free update by Apple. The speed, especially the responsiveness of the user interface, has been significantly improved and missing features, such as playing DVDs, have been added. The last version was Mac OS X 10.1.5 dated June 5, 2002.

Mac OS X Server 10.1 , server edition:
This server edition appeared at the same time as the desktop edition.

Mac OS X 10.2 ("Jaguar")

Mac OS X 10.2 :
Jaguar was released on August 13, 2002. With Quartz Extreme, it accelerated the user interface on suitable graphics cards. CUPS was introduced as the printing system , which enabled the use of alternative printer drivers. The last version of Jaguar was Mac OS X 10.2.8 (released October 3, 2003); however, there were a few security updates thereafter. Since this version, the big cats are not just code and project names, but official product names that are printed on the packaging and data carriers.

Mac OS X Server 10.2 :
This server release of Mac OS X 10.2 was released approximately 1½ weeks after the desktop release on August 24, 2002.

Mac OS X Panther 10.3

Mac OS X Panther 10.3 :
Panther was introduced on October 24, 2003. It brought features such as Exposé , the video chat program iChat AV and the user directory encryption FileVault . The new programming interface Core Audio has also been added. The Finder has been revised and some inconsistencies and inconsistencies of the previous version have been eliminated. In addition, the user interface has undergone some changes, the design has become a bit simpler overall. The system speed was further increased. With the newly introduced fast user switching, it was possible to switch back and forth between users without having to log off. The last version, Mac OS X 10.3.9, was released on April 15, 2005.

In contrast to version 10.2 (Jaguar), Panther (without third-party programs such as XPostFacto) can no longer be installed on the beige G3 Power Macs , but only on so-called "New World" Macs (with a different bus architecture, on the built-in USB ports and recognizable from the monochrome apple as the company logo on the housing).

Mac OS X Server 10.3 :
Mac OS X Server 10.3 was released at the same time as Panther on October 24, 2003.

Mac OS X Tiger 10.4

Steve Jobs at WWDC 2005. In the background you can see that he is using Mac OS X Tiger version 10.4.1 on an Intel instead of a PowerPC processor.

Mac OS X Tiger 10.4 :
Tiger was released on April 29, 2005. Among the innovations is a system-wide metadata search called Spotlight . With Dashboard , a new component has been added to Exposé that displays small auxiliary programs, so-called widgets . In addition, Tiger includes limited support for 64-bit - processes (on 64-bit processors) and the new programming interfaces Core Image and Core Video to outsource graphic calculations on the GPU of the graphics card . Officially, as of version 10.4.4, the system runs on Intel processors with i386 or IA-32 - instruction set architecture . The newly introduced Rosetta enables PowerPC applications to be run on Intel CPUs. System updates are offered separately as PowerPC or Intel versions. At over two years old, Tiger is the longest-maintained version of Mac OS X. On November 14, 2007, the last version of Tiger, 10.4.11 was released.

Mac OS X Server 10.4 :
This server edition was released together with the desktop edition on April 29, 2005. Mac OS X Server 10.4.7 (2006) was the first universal version of Mac OS X at all.

Mac OS X Leopard 10.5

Leopard was released on October 26, 2007 after the release date was postponed by about half a year due to capacity reasons (to the timely completion of the iPhone mobile phone ).

In Leopard, the user interface of the system and especially the Finder has been significantly revised; the concept of virtual desktops was adopted by some Linux variants with Spaces . The data backup software Time Machine and Boot Camp , which enable Windows to be installed in parallel with Mac OS X on Intel-based Macs, are also integrated . Leopard enables 64-bit operation for applications with a graphical user interface. In addition, it is the first BSD derivative ever to meet the Open Group's Single UNIX Specification UNIX 03 commercial certification and is therefore allowed to use the brand name “UNIX” (in capital letters or small caps ).

The Classic environment was discontinued with Mac OS X Leopard (10.5); Mac OS 9 or older Macintosh programs can no longer be run.

Mac OS X Server 10.5 :
At the same time as Leopard,
Mac OS X Server 10.5 was released on October 26, 2007, also as a universal version.

Mac OS X Snow Leopard 10.6

Snow Leopard was released on August 28, 2009. As already announced by Apple at WWDC on June 9, 2008, this operating system version contains mainly improvements and only a few new functions, in addition to the newly added App Store (requirement for operating system upgrades). The focus is on the improved utilization of the computer hardware - computers with PowerPC processors are no longer supported from this version, an Intel processor is therefore a requirement. So to with Grand Central Dispatch and Open Computing Language , a significant increase in performance by combining multi-core - CPUs with powerful graphics processors ( GPGPU ) can be achieved under a central programming interface. There is also an extended 64-bit support in the kernel . The Finder has been completely rewritten and is now a 64-bit application. Most of the pre-installed programs from Apple now also run in 64-bit mode, but can be started in 32-bit if required. QuickTime X supports modern multimedia codecs better; In addition, there is native support for Microsoft Exchange 2007 in the programs Mail , Address Book and iCal . As of January 6, 2011, the application has been available to access the Mac App Store for Snow Leopard.

Mac OS X Server 10.6:
The last separate server release was Mac OS X Server 10.6, which, like Snow Leopard, was released on August 28, 2009. It can also only run on Macs and Xserve with Intel processors.

Mac OS X Lion 10.7

Lion was released on July 20, 2011. The innovations presented by Lion include the Launchpad, an overview of all installed programs based on iOS; improved handling of programs in full screen mode; Mission Control , a combined overview of Spaces, Exposé, Dashboard and running full-screen programs; FileVault2, which now also enables full-disk encryption. Various components of earlier operating system versions, in particular the Front Row media center interface , a pre-installed Java runtime environment and the Rosetta emulation software are no longer supported.

Lion is the last version that still has “Mac OS X” in its name and has already been advertised as “OS X Lion”.

The separate server edition has been discontinued, from now on server and configuration software will be offered as a program package via the Mac App Store .

OS X Mountain Lion 10.8

Mountain Lion was presented on February 16, 2012 and published on July 25, 2012 at a price of 17.99 euros or 20 francs. OS X Mountain Lion explicitly dispenses with the addition “Mac”, which previous versions of the operating system had.

The innovations include, above all, functions that have been taken over from the iOS subsidiary operating system, such as push notifications including the notification center, better connection to iCloud , the expansion of the iMessage protocol on the Mac, dedicated programs for reminders and notes, and the system-wide integration of social media Networks like Twitter, Facebook, Flickr and Vimeo.

OS X Mavericks 10.9

The successor version of Mountain Lion was released on October 22, 2013. It was presented on June 10, 2013 by Craig Federighi at WWDC as OS X Mavericks, which was named after the Mavericks surf spot south of San Francisco. Among other things, it offers new functions such as tabs and tagging in the Finder and improves the handling of multiple screens. The update to Mavericks is free for owners of Apple computers.

OS X Yosemite 10.10

The successor version of Mavericks was released on October 16, 2014. It was presented on June 2, 2014 at the Worldwide Developers Conference (WWDC) and is named OS X Yosemite, after Yosemite National Park . The changes include a. improved cooperation with iPhone and iPad and a revised operating system interface. For the first time, there was a public beta program for the software before it was released. The update to Yosemite is free for owners of Apple computers.

OS X El Capitan 10.11

This version is the successor to Yosemite and was released on September 30, 2015. It was presented on June 8, 2015 at the Worldwide Developers Conference . It was named after a monolith in Yosemite National Park . In addition to improvements in window management and new functions in the programs supplied with the system, the focus is on stability and performance improvements. The  3D graphics interface Metal , which was already introduced with iOS 8, is also available on Mac models from 2012 onwards from El Capitan.

macOS Sierra 10.12

The successor to El Capitan was released on September 20, 2016. The system was presented at WWDC on June 13, 2016 in San Francisco. The name change from OS X to macOS was chosen based on the manufacturer's other operating systems, iOS , watchOS and tvOS . There were only minor technical changes in this version. Apple highlights the integration of the Siri voice recognition and control service and the option of logging into the computer using the Apple Watch . In addition, a new file system with which USB sticks can be password-protected and improved memory management have been added. In the Anglo-Saxon countries, in China and Singapore, and later also in Switzerland, France and Hong Kong, the online payment service Apple Pay is to be introduced via the Safari web browser .

macOS High Sierra 10.13

The successor to Sierra was unveiled on June 5, 2017 at WWDC . Also in this version there are mainly changes to details and further improvements. Safari receives support against tracking and prevents automatically playing videos on websites. Apple Photos gets new views for imported pictures.

The major changes concern the introduction of the new APFS file system , the new Metal 2 video interface and H.265 as the video standard for 4K videos.

macOS Mojave 10.14

Mojave was unveiled at WWDC on June 4, 2018 and has been available since September 24, 2018.

macOS Catalina 10.15

Catalina was introduced at WWDC on June 3, 2019 and has been available since October 7, 2019. One of the big changes is the complete switch to 64-bit , which is accompanied by the fact that 32-bit programs are no longer supported. This also applies to some older programs from Apple itself, such as Aperture and QuickTime 7 . The carbon interface, which was limited to 32-bit until recently, is no longer included in Catalina. The innovations include a. a read-only AFPS volume and stricter System Integrity Protection (SIP), which should increase security, as well as full controllability with voice commands and with Sidecar a function to use an iPad as an additional monitor.

Server operating system variant and program package

"Mac OS X Server", which was sold separately up to version 10.6 (Snow Leopard), runs on all Mac models that are also compatible with the desktop version. Since Lion 10.7 (2011) there is no longer a separate server version of the operating system: Additional server and configuration software can now be obtained from the Mac App Store . The resulting operating system is named "macOS Server" (or "OS X Server", in 10.7 also "Lion Server") and also runs on all Mac models supported by the regular macOS.

Between 1999 and 2013, the current version of “Mac OS X Server” was delivered preinstalled on server models from the Power Mac (“Macintosh Server”), Xserve , Mac Pro and Mac mini series.



Apple does not mention any periods for which updates ( English updates ) are assured. Major versions with major innovations and under a new name have appeared annually since 2011. These were further developed for a year and then provided with security updates for two years, so that the three most recent main versions were covered. In addition, patches have sometimes been made available for critical vulnerabilities in older major versions.

The accompanying a major version applications are usually not maintained after the introduction of a new major version, to provide an incentive for upgrading ( english upgrade to offer) of the platform. There are two exceptions to this: Since the release of El Capitan 10.11, the Safari web browser , starting with version 9, is also offered for the two previous systems during the update, but not with the newly introduced features compared to the earlier systems, which are only can be used on the current operating system. This procedure also applies to Safari 10, which is part of macOS Sierra , and to Safari 11 when macOS High Sierra was released .

Rhapsody (Betriebssystem) Mac OS X Public Beta Mac OS X 10.0 Mac OS X 10.1 Mac OS X 10.2 Mac OS X Panther Mac OS X Tiger Mac OS X Leopard Mac OS X Snow Leopard Mac OS X Lion OS X Mountain Lion OS X Mavericks OS X Yosemite OS X El Capitan macOS Sierra macOS High Sierra macOS Mojave macOS Catalina


Language support

The macOS operating system and the Cocoa-using software running under it are implemented for multilingualism, so that a change of language does not require a new installation of a program version. Messages from the system and applications are displayed in the language that is configured as preferred in the system settings. Several languages ​​can be specified and prioritized there. Applications that do not offer the first preferred language will then use the second or third etc.

Since the texts to be output in Cocoa programs are usually not included in their binary code, but are bundled in separate files within the program package ( English app bundle  ), additional languages ​​or language variants can also be added later - free projects can thus offer unofficial translations.

Similar to the localization of applications, a preferred language order can also be configured for the integrated spell checker. A spell checker is not available for all languages. Third-party dictionaries can be added to support additional languages.

Siri is an assistant with speech recognition and output (audio user interface). Even before Siri was introduced, macOS was able to recognize voice commands and speak texts, see p. VoiceOver . These functions are also used for accessibility .

In general, the English language components in macOS offer the largest range of functions.

Integrated languages

The operating system is supported by the following languages ​​(partly in country-specific variants) Arabic, Chinese (traditional and simplified), German, Danish, English, Finnish, French, Greek, Hebrew, Hindi, Indonesian, Italian, Japanese, Catalan, Korean, Croatian, Malay , Dutch, Norwegian (Bokmål), Polish, Portuguese, Romanian, Russian, Swedish, Slovak, Spanish, Thai, Czech, Turkish, Ukrainian, Hungarian and Vietnamese.

VoiceOver supports 24 other languages ​​in addition to German and English.

Web links

Commons : macOS  - collection of pictures, videos and audio files

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