MacOS(originally named Mac OS X until 2012 and then OS X until 2016) is a series of proprietary graphical operating systems developed and marketed by Apple Inc. It is the primary operating system for Apple’s Mac computers. It is the second most widely used desktop OS, after Microsoft Windows.

Apple’s current Mac operating system began with the company’s project to replace its “classic” Mac OS, introduced in 1984. The final release of that series was Mac OS 9 which was released in 1999. The first desktop version, Mac OS X 10.0, was released in March 2001. After this, Apple began naming its releases after big cats (versions 10.0–10.8) or locations in California (10.9–present).


Mac OS X Public Beta

The Mac OS X Public Beta, code-named Kodiak, was an early, test version of the Mac OS X operating system released to the public on September 13, 2000 for USD $29.95. This version was used to gain feedback from users.


•The public beta marked the first public availability of the Aqua interface. Virtually everything was new in the operating system: fonts, the Dock, even the menu. The icons exploded in size, and new OS eye candy was all the rage.

Mac OS X 10.0 Cheetah

Mac OS X 10.0, code-named Cheetah, is the first official release of Apple Inc.’s operating system Mac OS X. Apple released this version on March 24, 2001. It was priced at $129.

New and Changed Features

The Dock. •The Mail application. •The Address Book.

•The Aqua interface. It is the visual interface theme of the Mac OS X operating system.

AppleScript. It is a scripting language for the Mac.

Preview: Support for viewing PDFs.

Many critics suggested that the operating system was not ready for mainstream adoption a number of reasons:

•Slow response •Stability •Lack of features

Mac OS X 10.1 Puma

Mac OS X 10.1, code-named Puma, is the second major release of Apple Inc.’s operating system Mac OS X. It was released on September 25, 2001. Apple released 10.1 as a free upgrade CD for 10.0 users, in addition to the US$129 boxed version for people running Mac OS 9.

New and Changed Features

•Performance enhancements everywhere in the system

•Easier CD and DVD burning right from the Finder

•DVD player support

•More printer support (200 printers supported out of the box)

•Faster 3D (OpenGL 20% faster)

Mac OS X 10.2 Jaguar

Mac OS X version 10.2 Jaguar, is the third major release of Apple Inc.’s operating system Mac OS X . It was released on August 23, 2002 and the first release to use its code name as part of the branding.

New and Changed Features

•Increased support for Microsoft Windows networks

•An adaptive spam mail filter

•A system-wide repository for contact information in the new Apple Address Book

iChat, an Apple-branded, officially-supported third party AOL Instant Messenger client

•A revamped Finder with searching built directly into every window

•Dozens of new Universal Access features

Sherlock 3: Web services

Mac OS X 10.3 Panther

Mac OS X version 10.3 Panther, is the fourth major release of Apple Inc.’s operating system Mac OS X. It was released on October 24, 2003. Apple charged USD 129.00 for a single-user license and USD 199.00 for a Family Pack (5 user, 1 household) license.

New and Changed Features

Apple claimed that Panther had at least 150 new features, including:

•Finder updated interface

Fast User Switching, that allows a user to remain logged in while another user logs in feature

Exposé, a window manager

TextEdit support for Microsoft Word (*.doc) documents.

iChat AV which added video-conferencing features to iChat

•PDF rendering speed increases

Mac OS X 10.4 Tiger

Mac OS X version 10.4 Tiger, is the fifth major update to Mac OS X for Apple’s Macintosh computers, and was released on April 29, 2005.

New and Changed Features

Mac OS X 10.4 contains over 200 new features.

Spotlight, a powerful full-text and Metadata search engine

iChat AV that supports up to 4 participants in a video conference and 10 participants in an audio conference.

•A new mini-applications layer based on HTML, CSS, and JavaScript called Dashboard.

•A scripting tool called Automator to link applications together to form complex automated workflows

VoiceOver, a spoken interface allowing the OS to read from the screen, and to permit operation of the OS by voice command.

•A new graphics processing API, Core Image, leveraging the power of the available accelerated graphics cards.

•A new data processing API, Core Data, that makes it easier for developers to handle structured data in their applications.

•An included Dictionary and thesaurus.

Grapher, a powerful mathetical program

Mac OS X 10.5 Leopard

Mac OS X version 10.5 Leopard, is the sixth major update to Mac OS X for Apple’s Macintosh computers, and was released on October 26, 2007. Leopard was the last OS released by Apple to support both the Intel and PowerPC architectures.

New and Changed Features

Mac OS X 10.5 brought more than 300 new features.

•The single DVD works for all supported Macs (including 64-bit machines).

•A new look

•An updated Finder

Time Machine

•Full support for 64-bit applications (including graphical applications)

•New features in Mail and iChat

•A number of new security features

Mac OS X 10.6 Snow Leopard

Mac OS X 10.6 Snow Leopard is the seventh major release of Mac OS X, Apple’s desktop and server operating system for Macintosh computers. On August 28, 2009, it was released worldwide, and was made available for purchase from Apple’s website and its retail stores at the price of US$29 for a single-user license.

New and Changed Features

•The disk space that the operating system frees up after a clean install compared to Mac OS X 10.5 Leopard was a noticeable change for most users.

•A more responsive Finder rewritten in Cocoa

•Faster Time Machine backups

•More reliable and user-friendly disk ejects

•A faster Safari web browser

•Snow Leopard also featured new 64-bit technology capable of supporting greater amounts of RAM, improved support for multi-core processors through Grand Central Dispatch, and advanced GPU performance with OpenCL.

Mac OS X 10.7 Lion

Mac OS X 10.7 Lion ( marketed as OS X Lion) is the eighth major release of Mac OS X, Apple’s desktop and server operating system for Macintosh computers. It was released on July 20, 2011. Apple reported over 1 million Lion sales on the first day of its release.

New and Changed Features

Apple states that there are over 250 new or changed features in Lion, including:

Address Book now uses an iPad-like user interface. It also includes improved Yahoo support and FaceTime calling.

AirDrop — Lion-to-Lion direct file sharing via Wi-Fi Direct.

Auto-correction & Auto Save

Emoji support

Finder improvements — Finder search allows multiple search criteria to be specified without creating a smart folder, Finder search offers suggestions, files can be grouped by various attributes, and one can now merge files under two folders with the same name — a prompt will appear asking whether one wants to replace or keep both files.

Full-screen apps Launchpad Mac App Store

High-quality multilingual speech voices — users can download new high-quality voices in more than forty languages and dialects.

iChat now has support for logging into Yahoo! Messenger. Users can audio- and video-chat with other iChat users using their Yahoo! accounts.

Multi-touch gestures — Similar to iOS, additional gestures performed using a multi-touch input device (e.g. Magic Mouse, Magic Trackpad) will allow the user to scroll, swipe to different pages, and enter Mission Control

QuickTime re-incorporates some features from QuickTime Pro. New features cited include Copy/Paste, Insert Clip, Crop Video, Rotate Video, Resize, Trim, and more Export options.

Safari — With full-screen mode and the new WebKit2 Web browser engine.

TextEdit gains a new graphical toolbar with font selection and text highlighting.

Dropped features

Front Row, a media center application

Rosetta, software which makes possible the execution of PowerPC software on x86 hardware

Adobe Flash Player and Apple’s Java Runtime Environment (JRE), but both can still be downloaded and installed manually.

iSync, software used for syncing contacts and calendars to third-party mobile phones

Apple USB Modem

Mac OS X 10.8 Mountain Lion

OS X 10.8, also known as “Mountain Lion”, is a Macintosh operating system developed by Apple Inc. It’s goal was to start incorporating features found in iOS to the Macintosh User Interface. It was released on July 25, 2012 from the Mac App Store for $19.99.

New and Changed Features

iCloud will be using it for iMessages, Reminders, Game Center, Mail, Notes, and many other features.

Notification Center will have notifications about your Mac and Mac Apps, along with your other iDevices that have iCloud set up.

Share Sheets

Twitter — You will be able to tweet right from your apps. Also when you get a mention or a direct message, a Twitter notification appears on your desktop.

Game Center — You will be able to see what your friends are doing, check your stats, and more just like you have iOS.

GateKeeper helps prevent you from unknowingly downloading and installing malicious software. And it gives you control over which applications to download and run on your Mac.

Time Machine is able to do rotating backups on more than one storage medium.

•Address Book, iChat, iCal are renamed “Contacts”, “Messages” and “Calendar” respectively.

Dropped features

•RSS support in Mail and Safari has been removed

•Software Update has been unified into the Mac App Store

• — users are directed to the open source XQuartz project instead

OS X 10.9 Mavericks

OS X version 10.9, also known as “Mavericks”, is the tenth major release of OS X, Apple Inc’s desktop and server operating system for Macintosh computers. OS X Mavericks was released on October 22, 2013, as a free update through the Mac App Store. Mavericks marks the beginning of a change in the naming scheme of OS X, departing from the use of big cats and moving to names based on places in California. The new naming scheme also removes the “Mac” prefix from the name.

New and changed features

•Improved multiple display support: The menu bar and the Dock can be accessed on each display; Apple TV can be used as an external display.

•Finder enhancements, including tabs, fullscreen support, and document tags.

•Added new iBooks & Maps applications.

•Calendar & Safari browser enhancements.

•Timer coalescing, which enhances energy efficiency by reducing CPU usage by up to 72%.

•App Nap, which sleeps apps that are not currently visible.

•Server Message Block version 2 (SMB2) is now the default protocol for sharing files.

•LinkedIn sharing integration.

•OpenGL 4.1 Core Profile.

•OpenCL 1.2.

•USB syncing of calendar, contacts and other information to iOS devices has been removed, instead requiring the use of iCloud.

•Some system alerts, such as low battery and removal of drives without ejecting, have been moved to Notification Center.

OS X 10.10 Yosemite

OS X version 10.10, also known as “Yosemite”, is the eleventh major release of OS X, Apple Inc’s desktop and server operating system for Macintosh computers. OS X Yosemite was released to the public on October 16, 2014, as a free update through the Mac App Store.

New and Changed Features

Flattened 3D interface and presented a darker “night theme” and translucent Windows 7-like elements

Spotlight is more tightly integrated into Application data and provides its own viewing interface — for both local and web-based sources.

Today view in Notification Center — provides a single location for all of the current day’s events and items

iCloud Drive adds Apple-branded Finder-integrated cloud storage, similar to DropBox and Google Drive. Also, has a Windows and Web-based interface

Safari updated, UI simplified, default search changed to Bing from Google, added Private Browsing mode and DuckDuckGo search

Mail handles large attachments more intuitively, allows PDF annotating, and includes Mail Drop for quick emailing of messages with attachments, where the attachments get encrypted in iCloud instead of sent via email

Instant Hotspot makes using your iOS 8+ iPhone for network connectivity as easy as connecting to a Wi-Fi network

iPhone Calls can be made from the OS X desktop


OS X 10.11 El Capitan

OS X version 10.11, “El Capitan”, is the twelfth major release of OS X, Apple Inc.’s desktop and server operating system for Macintosh computers. El Capitan was named after a rock formation in Yosemite National Park. OS X El Capitan was released on September 30, 2015, as a free upgrade through the Mac App Store.

New and changed features

•Apple described this release as containing “refinements to the Mac experience” and “improvements to system performance” rather than new features.

Refinements include:

•Public transport built into the Maps application

•GUI improvements to the Notes application

•Adopting San Francisco as the system font for clearer legibility

•The introduction of System Integrity Protection.

•The Metal API, first introduced in iOS 8, was also included in this operating system. According to Apple, Metal accelerates system-level rendering by up to 50 percent, resulting in faster graphics performance for everyday apps. Metal also delivers up to 10 times faster draw call performance for more fluid experience in games and pro apps.

macOS 10.12 Sierra

macOS 10.12 Sierra is the thirteenth major release of OS X, renamed macOS, Apple’s desktop and server operating system for Macintosh computers. It was released September 20, 2016 as a free upgrade through the Mac App Store. Sierra was named after the entire Sierra Nevada mountain range that includes Yosemite National Park and Lake Tahoe.

New and changed features

Siri integration, including drag-and-drop

Auto Unlock via paired devices such as an Apple Watch

Universal Clipboard shared between devices using the same Apple ID

Desktop and Documents Sync, syncing the desktop and documents folders via the cloud so the same desktop is available everywhere

Apple Pay Integration, where linked devices with Apple Pay can be used to pay via Safari.

Messages gets a major refresh and now allows users to integrate rich media into one’s texts

Apple Music is fully rebranded and has a new interface

Optimized Storage, where old items can be moved off-disk onto iCloud storage

Safari-style Tabs, where tabs are now a UI feature inherited by Cocoa applications, not just Safari, Terminal and the Finder.

macOS 10.13 High Sierra

macOS 10.13 High Sierra is the fourteenth major release of OS X, renamed macOS, Apple’s desktop and server operating system for Macintosh computers. It was released on September 25, 2017, as a free upgrade through the Mac App Store. High Sierra was named after the High Sierras in the Sierra Nevada mountain range.

New and Changed features

Metal 2, adds a newer version of the graphics display system, which supports VR and extended GPU functionality at higher speeds.

Integrated VR support, contains support for creating, editing and interacting with VR media.

Photos, adds an expanded sidebar, improved organization tools, integrates with advanced editing tools, supports more Memories modules and live photo editing tools, and included People/Faces.

Safari, now contains Intelligent Tracking Prevention, the ability to disable autoplay, site-based browser settings, site-based always-on reader view.

Siri, supports preference learning for music and is more tightly integrated with iTunes, and text to speech is improved.

Spotlight, adds flight tracking features.

Mail Search, is improved with more options.

Facetime, supports capture of Live Photos from streaming video.

Notes, adds pins and tables.

macOS 10.14 Mojave

macOS 10.14 Mojave ,released on September 24, 2018, is the fifteenth major release of OS X, renamed macOS, Apple’s desktop and server operating system for Macintosh computers. Mojave was named after the Mojave Desert.

New and Changed Features:

•Dark Mode transforms the desktop with a dark color scheme that highlights content and makes it easier on the eyes, especially when working in low light such as in a darkened room or on an airplane.

•Stacks quickly clears cluttered desktops by automatically organizing files into neat groups based on file types like images, presentations, PDFs and text documents.

•Dynamic Desktop-The desktop, featuring the rolling sand dunes of the Mojave Desert, transitions with different lighting variations based on the time of day, from dawn to morning, midday, dusk and evening to give the Mac user an all-new experience.

•Finder in macOS Mojave features an all-new Gallery View that lets users skim through files visually, while a Preview Pane shows all of a file’s metadata, making it easier to manage media assets.

•Screenshots delivers easy-to-use on-screen controls for quick access to screenshot options and new video recording capabilities.

•Continuity Camera-With Continuity Camera users can shoot or scan a nearby object or document using their iPhone, and have it appear on their Mac.

•New Apps: News, Stocks, Voice Memos and Home

•New Mac App Store features rich editorial content that makes it easier than ever to find Mac apps and a number of great new apps including productivity tools like Omni Focus 3 and games like Alto’s Adventure and The Gardens Between.

•Safari-In Safari, enhanced Intelligent Tracking Prevention helps prevent social media “Like” or “Share” buttons and comment widgets from tracking users without permission.

macOS 10.15 Catalina

macOS 10.15 Catalina , released on October 7, 2019, is the sixteenth major release of OS X, renamed macOS, Apple’s desktop and server operating system for Macintosh computers. Catalina was named after Santa Catalina Island, located in Southern California.

New products and features

iTunes is broken up into multiple other products.

•The Finder is now used for syncing iOS devices, including software and ringtone management

•Music is managed through Apple Music, TV and Movies are provided through Apple TV, audio podcasts are provided through Apple Podcasts.

Catalyst is a new API that allows software originally designed for iPad OS to also function on macOS.

Apple Arcade is a new subscription-based section of the App Store that provides access to the same games and game data across macOS, iOS, iPadOS and tvOS.

Sidecar is a new feature that lets you use a device running iPadOS 13 or later as a wireless secondary extended or mirroring monitor.

Activation Lock has been added for all hardware using the T2 security chip.

Find has replaced Find My iPhone and Find My Friends in iCloud and on iOS devices, and is now available on macOS as well.

•Authentication handling can now be done from an Apple Watch as well as the fingerprint reader or FaceID where available.

Apple Photos has been updated with improved visualization and sorting features.

Notes now has a gallery view, better checklist handling, and improved collaboration tools.

Safari has minor improvements, including new privacy features, Messages integration and Siri Suggestions integration.

BSc.(Hons) Software Engineering Undergraduate | University Of Kelaniya