Evolution of Mac OS.

Macintosh operating systems (Mac OS) is developed by an American company Apple Inc.this OS also a main operating system that use in whole world.Mac OS starts the journey from version 10.0.but before that they released a trail version. These are some information about the history of Mac OS.

Mac OS X Public Beta: “Kodiak”

This is the first attempt of mac OS. On September 13, 2000, Apple released the version of Mac OS X (internally code named Kodiak) in order to gain feedback from users.It marked the first public availability of the Aqua interface, and Apple made many changes to the User interface based on customer feedback. Mac OS X Public Beta expired and ceased to function in spring 2001.

Mac OS X 10.0 :“Cheetah”

Apple released Mac OS X 10.0 ( Cheetah) on March 24, 2001.this version was very slow and incomplete one.Many critics suggested that the operating system was not ready for mainstream adoption but Macintosh community take that as a great accomplishment, for attempts to completely overhaul the Mac OS had been underway since 1996.

Darwin version :-1.3.1
Processor :-32-bit PowerPC
support Application :-32-bit PowerPC
support Kernel :-32-bit

Mac OS X 10.1 : “ Puma”

After few months Apple released Mac OS X 10.1 ( Puma) on September 25, 2001.The missing things in “cheetah” like DVD playback were included to this version and apple released free upgrade CDs for 10.0 users. apple announced that they will use Mac OS X as there default OS for all Macintosh products on January 7, 2002.

Mac OS X 10.2 : “Jaguar”

In next year on August 23, 2002 apple were released Jaguar and the used the code name to brand the new version. It brought great raw performance improvements, a sleeker look, and many powerful user-interface enhancements.The Happy Mac which had appeared during the Mac OS startup sequence for almost 18 years was replaced with a large grey Apple logo with the introduction of Mac OS X version 10.2.

Mac OS X 10.3 : “Panther”

On October 24, 2003 apple released the next version Mac OS X 10.3 panther with more improved performances. panther was updated with including an updated Finder, incorporating a brushed-metal interface, Fast user switching, Expose(Window manager), File Vault, Safari, i-Chat AV (which added videoconferencing features to i-Chat), improved Portable Document Format (PDF) rendering and much greater Microsoft Windows interoperability.

Mac OS X 10.4 : “Tiger”

Tiger version was released on April 29, 2005 with more than 200 new features. But as with Panther, certain older machines were no longer supported to the tiger and requires a Mac with 256 MB and a built-in Fire-wire port. Among the new features, Tiger introduced Spotlight, Dashboard, Smart Folders, updated Mail program with Smart Mailboxes, QuickTime 7, Safari 2, Automator, VoiceOver, Core Image and Core Video.

Mac OS X 10.5 : “Leopard”

On October 26, 2007 Mac OS X 10.5 leopard was released with more than 300 new features. It was called by Apple “the largest update of Mac OS X”. Leopard requires the G4 processor required a minimum clock rate of 867 MHz, and at least 512 MB of RAM to be installed.Leopard is an Open Brand UNIX 03 registered product on the Intel platform.It was also the first BSD-based OS to receive UNIX 03 certification. Leopard dropped support for the Classic Environment and all Classic applications.It was the final version of Mac OS X to support the PowerPC architecture.

Mac OS X 10.6 : “Snow Leopard”

Mac OS X 10.6 Snow Leopard was released on August 28, 2009. Snow Leopard focused on “under the hood” changes, increasing the performance, efficiency, and stability of the operating system. faster Time Machine backups,faster Safari web browser were some noticeable changes in Snow Leopard. Snow Leopard only supported machines with Intel CPU s, required at least 1 GB of RAM.this version 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. The 10.6.6 update introduced support for the Mac App Store, Apple’s digital distribution platform for mac OS applications

Mac OS X 10.7 : “Lion”

Mac OS X 10.7 Lion was released on July 20, 2011. New features such as an easily navigable display of installed applications called Launchpad and a greater use of multi-touch gestures, were added to the Mac. It dropped support for 32-bit Intel processors and requires 2 GB of memory. The method that Documents auto-save by default was in this lion version.

OS X 10.8 : ”Mountain Lion”

OS X 10.8 Mountain Lion was released on July 25, 2012. Game Center, support for i-Message in the new Messages messaging application, a to-do list app separate from i-Cal, storing i-Work documents in i-Cloud were some features that were in Mountain Lion and it was a desktop version similar to the one in iOS 5.0.

OS X 10.9 : “Mavericks”

Apple released the OS X 10.9 Mavericks to users at free for slow users of Snow Leopard or later with a 64-bit Intel processor on October 22, 2013. Its changes include the addition of the previously iOS-only Maps and iBooks applications, improvements to the Notification Center, enhancements to several applications, and many under-the-hood improvements. Mavericks requires 2 GB of memory to operate.

OS X 10.10 : “Yosemite”

OS X 10.10 Yosemite was released on October 16, 2014 for users at free of charge like last version and this version user interface similar to that of iOS 7.Yosemite enables users with iPhone s running iOS 8.1 or later to answer phone calls, receive and send SMS messages, and complete unfinished iPhone emails on their Mac by introducing new feature “Handoff”.

OS X 10.11 : “El Capitan”

OS X 10.11 El Capitan was released on September 30, 2015 with more
similarities to snow leopard version. Apple described this release as containing “refinements to the Mac experience” and “improvements to system performance” rather than new features. Maps application,GUI improvements to the Notes application, San Francisco as the system font for clearer legibility and security improvements were included in El Capitan.

mac OS 10.12 : “Sierra”

On September 20, 2016 mac OS 10.12 Sierra was released with new improvement like searching for files option. iCloud also received several improvements, such as the ability to store a user’s Desktop and Documents folders on iCloud so they could be synced with other Macs on the same Apple ID. Mac OS Sierra requires at least 2 GB of RAM and 8 GB of storage space and will run on.

mac OS 10.13 : ”High Sierra”

Mac OS 10.13 High Sierra was released to the public on September 25, 2017. High Sierra is a refinement-based update having very few new features visible to the user, including updates to Safari, Photos, and Mail, among other changes and require at least 2 GB GB of RAM.

mac OS 10.14 : “Mojave”

Mac OS 10.14 Mojave was released on September 24, 2018.The update introduced a system-wide dark mode as the new feature, Desktop stacks and Dynamic Desktop, which changes the desktop background image to correspond to the user’s current time of day and several new apps lifted from iOS, such as Apple News. Mac OS Mojave requires at least 2 GB of RAM as well as 12.5 GB of available disk space to upgrade from OS X El Capitan, mac OS Sierra, or mac OS High Sierra or 18.5 GB of disk space to upgrade from OS X Yosemite and earlier releases. Some features are not available on all compatible models.

mac OS 10.15 : “Catalina”

On October 7, 2019 mac OS 10.15 Catalina was released. This OS is included with lots of additional new features like sharing your screen to iPad (Sidecar) and is capable of running iPad apps. It primarily focuses on updates to built-in apps, such as replacing iTunes with separate Music, Podcasts, and TV apps, redesigned Reminders and Books apps, and a new Find My app.Catalina requires 4 GB of memory, an increase over the 2 GB required by Lion through Mojave

This is some brief information that I found. How ever now a day apple Inc still dong there roll to develop the technology. I think you got some idea from this. Thankyou for reading.