Evolution of Mac OS

dilusha sandaruwani
9 min readAug 6, 2020


Mac OS is a series of graphical user interface- based operating systems developed by Apple Inc. for their Macintosh line of computer systems. Apple computers run the Mac OS X, the second most used operating system in the world. It’s been more than 34 years after it was unveiled and since then, it has been praised for its simplicity, intuitiveness, and aesthetic quality. This operating system is designed to be easy to use and engineered to take full advantage of the technologies built into every computer we make.

The history of macOS, Apple’s current Mac operating system originally named Mac OS X until 2012 and then OS X until 2016, began with the company’s project to replace its “classic” Mac OS. That system, up to and including its final release Mac OS 9, was a direct descendant of the operating system Apple had used in its Macintosh computers since their introduction in 1984. However, the current macOS is a Unix operating system built on technology that had been developed at NeXT from the 1980s until Apple purchased the company in early 1997.

OS X was introduced at WWDC 2004. It included a universal search client, Spotlight, which allowed users to search their entire system from the menu bar for files, emails, contacts, images, calendars and applications. Dashboard featured widgets for weather, flight information, stock tickers and more. Safari included RSS features and iChat supported up to four participants in a video conference or 10 participants in an audio conference.

OS X 10.4 also introduced Automator, an application that automated tasks and workflows such as renaming large groups of files or resizing dozens of images; and VoiceOver, an accessibility interface that provided magnification options, keyboard control and spoken English descriptions of what’s happening on screen.

OS X Tiger became the first OS to support the Apple-Intel architecture after Apple’s transition to Intel x86 processors, and it became the longest running version of Mac OS X prior to Leopard’s release 30 months later.

The Evolution of Mac OS Versions:

The First Mac OS

The Macintosh “System 1” is the first version of Apple Macintosh operating system and the beginning of the classic Mac OS series. It was developed for the Motorola 68000 microprocessor. System 1 was released on January 24, 1984, along with the Macintosh 128K, the first in the Macintosh family of personal computers. It received one update, “System 1.1” on December 29, 1984, before being succeeded by System 2

Mac OS X 10 Public Beta

Prior to the release of the first Mac OS X version, the public beta, known inside Apple as Kodiak, was released by the company to developers to test the operating system and create software in time for the final release.

It is the first operating system to introduce the Aqua user interface — which is still used up until today. It was launched in September 2000 and it cost $29.95 to purchase. It became unsupported after March 24th 2001.

Mac OS X 10.0 Cheetah

Apple started the trend of naming its operating systems after big cats with Mac OS X 10.0, code name: Cheetah. It was the final nail in the coffin for Mac OS 9 and was released in March 24, 2001. It introduced the Dock, Mail, TextEdit, and still had Sherlock.

However, it was negatively received by the public for a variety of reasons:

  • It required 128 RAM at a time when the standard for Apple-made computers were at 64 MB.
  • The Aqua UI was slow and sluggish: the earlier operating systems were faster compared to it.
  • It had stability issues and was riddled with numerous bugs which caused kernel panics.
  • Hardware and compatibility issues, like missing DVD playback, not having a CD burning feature, and missing hardware driver issues.

The Cheetah as priced at $129, but it was so bad that it wasn’t worth the money and it rendered Apple to offer the next version for free.

Mac OS X 10.1 Puma

It was introduced later in September 2001, six months after Cheetah was released. It was handed out free of charge to Cheetah users. Though it fixed several bugs and areas where the Cheetah was lacking, it was not a significant upgrade and system crashes were still a norm.

Unlike its predecessor, Puma now had CD and DVD burning capabilities, playback support, and introduced several performance enhancements.

Mac OS X 10.2 Jaguar

Unlike the Cheetah and Puma, Apple the operating system’s code name, Jaguar, for marketing and advertisement purposes. It was released nearly a year after Puma, at August 24, 2002. The released featured single installation versions and family packs, which allowed it to be installed to up to five devices.

It was well-received by most Mac users, considering that most of the performance issues in the previous versions were addressed. It includes features which are still present in Macs up to this day, like MPEG-4 support for Quicktime, the Address Book, and Inkwell. Its most significant additions were Apple Mail and a messaging client called iChat, which was subsequently replaced with the Messages app after Mountain Lion.

Mac OS X 10.3 Panther

The Panther was released to the public on October 24, 2003, more than a year after Jaguar’s release. It was one of Apple’s biggest releases, considering that it introduced numerous updates and features (150, as claimed by Apple), including:

  • Finder, which had a new live search engine.
  • TextEdit, which became compatible with Microsoft Word docs.
  • Exposé, which helps users manage their Windows.

It’s biggest change and addition is the introduction of the Safari browser, which effectively replaced the Internet Explorer. It needed at least 128 MB of RAM to run. It also introduced XCode, Apple’s developer tool which helps develop applications, along with FileVault which is used to encrypt data.

Mac OS X 10.4 Tiger

The Tiger was met with a roaring reception after it was made public on April 29, 2005 — it became Apple’s bestselling operating system, selling over two million copies within six weeks after release. It boasted a slew of new features, including:

  • Spotlight — it effectively replaced Sherlock as the OS X internal search engine.
  • Mail 2 — a newer and improved version of the Mail app.
  • Dashboard — an app which featured widgets like a world clock, weather, and unit converter.
  • Dictionary — this uses the New Oxford American Dictionary.

Tiger also introduced Automator, Grapher, and Quicktime 7.

Mac OS X Leopard 10.5

As the successor to Tiger, the Leopard had big shoes to fill — and it did so to full capacity. It was released two years after its predecessor and was priced at $129 for the desktop version and $499 for the server one. According to Apple, it brought over 300 new features and numerous improvements. The notable ones include:

  • Security enhancements such as application signing, sandboxes, and library randomization.
  • Time Machine, a utility tool which allows the user to back up deleted or replaced files.
  • Quick Look, this allows documents to be viewed on a separate application without having to open them.
  • iCal now allows calendar sharing and group scheduling. It is also closely synced with the Mail app as well and the icon shows the date even when not in use.

Apart from these, Spaces and Boot Camp are also pre-installed.

Mac OS X 10.6 Snow Leopard

The Snow Leopard was priced at a pretty affordable $29, a huge markdown from the previous versions which cost a hundred dollars more. In terms of features, it did not deliver a lot considering that Apple focused more on performance and stability. It was more of an upgrade to the Leopard instead of a totally new operating system.

Here’s a list of improvements and upgrades separating it from the Leopard:

  • It freed up hard disk space considering that it was relatively smaller compared to the Leopard. It managed to give users an extra seven gigabytes of storage space.
  • The Finder was completely rewritten in Apple’s native application programming interface Cocoa, making it faster and more responsive.
  • A faster Safari browser and new features such as Top Sites, Cover Flow, and VoiceOver.

Snow Leopard also made improvements on the user interface which were more centered in making it easy to use.

Mac OS X 10.7 Lion

It was unveiled in October 2010 and was released to the public on July 1, 2011. It supported multi-touch features to the Mac and applications now open in the same state as they were closed, just like in the iOS. Speaking of the mobile operating system, the Lion also took a leaf out of its book, including a better and more navigable application display. The OS X notification also debuted in the operating system.

The Lion also included support for the Mac App Store and could support emojis.

OS X 10.8 Mountain Lion

As of OS X 10.8 Mountain Lion, Apple dropped “Mac OS X” and started marketing its operating systems as OS X. It was released in July 25 2012 and introduced new features which are present in the iOS 5, including the Game Center, iMessage support, Reminders as a separate app from iCal, which in turn was renamed to Calendar. Notes — and iOS app — was also added in the operating system which can then be synced to other Apple devices.

It sold 28 million copies in its first year, making it one of the most successful operating systems released by Apple.

OS X 10.9 Mavericks

Apple stopped naming its operating systems after big cats in OS X 10.9, which was named after a surfing spot in California. The default desktop background would suggest that.

It was released in October 23, 2013 as a free update. In a nutshell, Mavericks emphasized prolonged batter life and close integration with iOS. It was a significant update for Apple fans, given that it brought Apple Maps to the OS X, improved iCloud integration, and had the iBooks application.

OS X 10.10 Yosemite

If you haven’t upgraded your operating system to the current version, you might still be running Yosemite. It followed the landmark-based naming scheme Apple started with Mavericks — this time it was named after a prominent national park in California. The biggest change is the graphic interface, which now featured flat designs like those in iOS, effectively replacing skeumorphism.


OS X 10.11 El Capitan

El Capitan was released just a month ago, and completely stabilized and improved from Yosemite’s flaws. While it’s not a eature-rich update, it hosts a slew of improvements starting from the Safari browser, Apple Maps, and the new Split-screen feature, which allows users to work on two programs at the same time.

The release was met with positive reviews, praising its multi-tasking features and better iOS integration.

The latest version of macOS: Catalina

Apple’s newest Mac operating system is macOS 10.15, also known as macOS Catalina, which Apple released on October 7, 2019. This is the fifteenth major release of the Mac operating system.

Catalina removes iTunes, splitting it into separate Music, TV, and Podcastsapps. It completely removes support for any old 32-bit applications you may still be using. With Sidecar, you can use your iPad as a secondary display for your Mac. You can even use an Apple Pencil on an iPad’s screen to draw in applications on your Mac.

Apple releases a new major version roughly once every year. These upgrades are free and are available in the Mac App Store.

Thank you 😊.



dilusha sandaruwani

Software Engineering undergraduate at University of Kelaniya