For an overview of the features of the various versions of the Mac operating system, showing how it has developed over time, take a look at our video above. If you want to know the names Apple assigned to Mac OS X over the years, and the codenames that were used internally, read on.
As you can see from the list above, with the exception of the first OS X beta, all versions of the Mac operating system from 2001 to 2012 were all named after big cats, from Cheetah to Panther to the final release, Mountain Lion.
In 2016, Apple took the plunge to unify the branding of its operating systems by rebranding Mac OS X to macOS, which sits nicely alongside iOS, tvOS, and watchOS, and paved the way for macOS 11, the successor to Mac OS X, which arrived twenty years after the first beta of Mac OS X.
However, that changed slightly with Mojave, which arrived in 2018. Now operating system updates come in via a new Software Updates pane in System Preferences. You can still find the software in the Mac App Store, but you will also see it in System Preferences > Software Update. One of the benefits of this is that your Mac can be set to automatically download the latest updates and install them, keeping your Mac up-to-date with minimum effort on your part.
In 1984, Apple debuted the operating system that is now known as the \"Classic\" Mac OS with its release of the original Macintosh System Software. The system, rebranded \"Mac OS\" in 1997, was pre-installed on every Macintosh until 2002 and offered on Macintosh clones for a short time in the 1990s. Noted for its ease of use, it was also criticized for its lack of modern technologies compared to its competitors.
Prior to the introduction of Mac OS X, Apple experimented with several other concepts, releasing different products designed to bring the Macintosh interface or applications to Unix-like systems or vice versa, A/UX, MAE, and MkLinux. Apple's effort to expand upon and develop a replacement for its classic Mac OS in the 1990s led to a few cancelled projects, code named Star Trek, Taligent, and Copland.
Although they have different architectures, Mac operating systems share a common set of GUI principles, including a menu bar across the top of the screen; the Finder shell, featuring a desktop metaphor that represents files and applications using icons and relates concepts like directories and file deletion to real-world objects like folders and a trash can; and overlapping windows for multitasking.
The \"classic\" Mac OS is the original Macintosh operating system that was introduced in 1984 alongside the first Macintosh and remained in primary use on Macs until the introduction of Mac OS X in 2001.
Apple released the original Macintosh on January 24, 1984; its early system software was partially based on the Lisa OS and the Xerox PARC Alto computer, which former Apple CEO Steve Jobs previewed. It was originally named \"System Software\", or simply \"System\"; Apple rebranded it as \"Mac OS\" in 1996 due in part to its Macintosh clone program that ended a year later.
Classic Mac OS is characterized by its monolithic design. Initial versions of the System Software run one application at a time. System 5 introduced cooperative multitasking. System 7 supports 32-bit memory addressing and virtual memory, allowing larger programs. Later updates to the System 7 enable the transition to the PowerPC architecture. The system was considered user-friendly, but its architectural limitations were critiqued, such as limited memory management, lack of protected memory and access controls, and susceptibility to conflicts among extensions.
Nine major versions of the classic Mac OS were released. The name \"Classic\" that now signifies the system as a whole is a reference to a compatibility layer that helped ease the transition to Mac OS X.
Although the system was originally marketed as simply \"version 10\" of Mac OS, it has a history that is largely independent of the classic Mac OS. It is a Unix-based operating system built on NeXTSTEP and other technology developed at NeXT from the late 1980s until early 1997, when Apple purchased the company and its CEO Steve Jobs returned to Apple. Precursors to the original release of Mac OS X include OPENSTEP, Apple's Rhapsody project, and the Mac OS X Public Beta.
The first desktop version of the system was released on March 24, 2001, supporting the Aqua user interface. Since then, several more versions adding newer features and technologies have been released. Since 2011, new releases have been offered on an yearly basis.
An early server computing version of the system was released in 1999 as a technology preview. It was followed by several more official server-based releases. Server functionality has instead been offered as an add-on for the desktop system since 2011.
The Apple Real-time Operating System Environment (A/ROSE) was a small embedded operating system which ran on the Macintosh Coprocessor Platform, an expansion card for the Macintosh. The idea was to offer a single \"overdesigned\" hardware platform on which third-party vendors could build practically any product, reducing the otherwise heavy workload of developing a NuBus-based expansion card. The first version of the system was ready for use in February 1988.
In 1988, Apple released its first UNIX-based OS, A/UX, which was a UNIX operating system with the Mac OS look and feel. It was not very competitive for its time, due in part to the crowded UNIX market and Macintosh hardware lacking high-end design features present on workstation-class computers. A/UX had most of its success in sales to the U.S. government, where POSIX compliance was a requirement that Mac OS could not meet.
The Macintosh Application Environment (MAE) was a software package introduced by Apple in 1994 that allowed users of certain Unix-based computer workstations to run Apple Macintosh application software. MAE used the X Window System to emulate a Macintosh Finder-style graphical user interface. The last version, MAE 3.0, was compatible with System 7.5.3. MAE was available for Sun Microsystems SPARCstation and Hewlett-Packard systems. It was discontinued on May 14, 1998.
Announced at the 1996 Worldwide Developers Conference (WWDC), MkLinux is an open source operating system that was started by the OSF Research Institute and Apple in February 1996 to port Linux to the PowerPC platform, and thus Macintosh computers. In mid 1998, the community-led MkLinux Developers Association took over development of the operating system. MkLinux is short for \"Microkernel Linux,\" which refers to the project's adaptation of the Linux kernel to run as a server hosted atop the Mach microkernel. MkLinux is based on version 3.0 of Mach.
Taligent (a portmanteau of \"talent\" and \"intelligent\") was the name of an object-oriented operating system and the company dedicated to producing it. Started as a project within Apple to provide a replacement for the classic Mac OS, it was later spun off into a joint venture with IBM as part of the AIM alliance, with the purpose of building a competing platform to Microsoft Cairo and NeXTSTEP. The development process never worked, and Taligent is often cited as an example of a project death march. Apple pulled out of the project in 1995 before the code had been delivered.
Copland was a project at Apple to create an updated version of the classic Mac OS. It was to have introduced protected memory, preemptive multitasking and a number of new underlying operating system features, yet still be compatible with existing Mac software. As originally planned, a follow-up release known as \"Gershwin\" would add multithreading and other advanced features. New features were added more rapidly than they could be completed, and the completion date slipped into the future with no sign of a release. In 1996, Apple decided to cancel the project outright and find a suitable third-party system to replace it. Copland development ended in August 1996, and in December 1996, Apple announced that it was buying NeXT for its NeXTSTEP operating system.
Before the arrival of the Macintosh in 1984, Apple's history of operating systems began with its Apple II series computers in 1977, which ran Apple DOS, ProDOS, and later GS/OS; the Apple III in 1980, which ran Apple SOS; and the Apple Lisa in 1983, which ran Lisa OS and later MacWorks XL, a Macintosh emulator. Apple also developed the Newton OS for its Newton personal digital assistant from 1993 to 1997.
In recent years, Apple has also launched several new operating systems based on the core of macOS, including iOS in 2007 for its iPhone, iPad, and iPod Touch mobile devices and in 2017 for its HomePod smart speakers; watchOS in 2015 for the Apple Watch; tvOS in 2015 for the Apple TV set-top box.
macOS (/ˌmækoʊˈɛs/; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and laptop computers it is the second most widely used desktop OS, after Microsoft Windows and ahead of ChromeOS.
macOS succeeded the classic Mac OS, a Mac operating system with nine releases from 1984 to 1999. During this time, Apple cofounder Steve Jobs had left Apple and started another company, NeXT, developing the NeXTSTEP platform that would later be acquired by Apple to form the basis of macOS.
The first desktop version, Mac OS X 10.0, was released in March 2001, with its first update, 10.1, arriving later that year. All releases from Mac OS X 10.5 Leopard and after are UNIX 03 certified, with an exception for OS X 10.7 Lion. Apple's other operating systems (iOS, iPadOS, watchOS, tvOS, audioOS) are derivatives of macOS.
A prominent part of macOS's original brand identity was the use of Roman numeral X, pronounced \"ten\" as in Mac OS X and also the iPhone X, as well as code naming each release