macOS version history
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.
To ease the transition for users and developers, versions 10.0 through 10.4 were able to run Mac OS 9 and its applications in the Classic Environment, a compatibility layer.
After Apple removed Steve Jobs from management in 1985, he left the company and attempted to create the "next big thing", with funding from Ross Perot[8] and himself.
It also supported the innovative Enterprise Objects Framework database access layer and WebObjects application server development environment, among other notable features.
[citation needed] All but abandoning the idea of an operating system, NeXT managed to maintain a business selling WebObjects and consulting services, only ever making modest profits in its last few quarters as an independent company.
NeXTSTEP underwent an evolution into OPENSTEP which separated the object layers from the operating system below, allowing it to run with less modification on other platforms.
However, by this point, a number of other companies — notably Apple, IBM, Microsoft, and even Sun itself — were claiming they would soon be releasing similar object-oriented operating systems and development tools of their own.
[citation needed] On February 4, 1997, Apple Computer acquired NeXT for $427 million, and used OPENSTEP as the basis for Mac OS X, as it was called at the time.
The decade-old Macintosh System Software had reached the limits of its single-user, co-operative multitasking architecture, and its once-innovative user interface was looking increasingly outdated.
A massive development effort to replace it, known as Copland, was started in 1994, but was generally perceived outside Apple to be a hopeless case due to political infighting and conflicting goals.
At first, the plan was to develop a new operating system based almost entirely on an updated version of OPENSTEP, with the addition of a virtual machine subsystem — known as the Blue Box — for running "classic" Macintosh applications.
Apple's financial losses continued and the board of directors lost confidence in CEO Gil Amelio, asking him to resign.
The Darwin kernel provides a stable and flexible operating system, which takes advantage of the contributions of programmers and independent open-source projects outside Apple; however, it sees little use outside the Macintosh community.
[citation needed] With the exception of Mac OS X Server 1.0 and the original public beta, the first several macOS versions were named after big cats.
On September 13, 2000, Apple released a $29.95[38] "preview" version of Mac OS X (internally codenamed Kodiak) in order to gain feedback from users.
[39] It marked the first public availability of the Aqua interface, and Apple made many changes to the UI based on customer feedback.
Critics suggested that the operating system was not ready for mainstream adoption, but they recognized the importance of its initial launch as a base to improve upon.
On January 7, 2002, Apple announced that Mac OS X was to be the default operating system for all Macintosh products by the end of that month.
[45] It brought great raw performance improvements, a sleeker look, and many powerful user-interface enhancements (over 150, according to Apple[46] ), including Quartz Extreme for compositing graphics directly on an ATI Radeon or Nvidia GeForce2 MX AGP-based video card with at least 16 MB of VRAM, a system-wide repository for contact information in the new Address Book, and an instant messaging client named iChat.
Panther included as many or more new features as Jaguar had the year before, including an updated Finder, incorporating a brushed-metal interface, Fast user switching, Exposé (Window manager), FileVault, Safari, iChat AV (which added videoconferencing features to iChat), improved Portable Document Format (PDF) rendering and much greater Microsoft Windows interoperability.
[49] As with Panther, certain older machines were no longer supported; Tiger requires a Mac with a built-in FireWire port.
The initial release of the Apple TV used a modified version of Tiger with a different graphical interface and fewer applications and services.
This operating system functioned identically on the PowerPC-based Macs and the new Intel-based machines, with the exception of the Intel release dropping support for the Classic environment.
For most users, the most noticeable changes were a difference in the disk space that the operating system frees up after a clean installation when compared to Mac OS X 10.5 Leopard, a more responsive Finder rewritten in Cocoa, faster Time Machine backups, more reliable and user friendly disk ejects, a more powerful version of the Preview application, and a faster Safari web browser.
It brought developments made in Apple's iOS, such as an easily navigable display of installed applications (Launchpad) and (a greater use of) multi-touch gestures, to the Mac.
[67] OS X Yosemite was released to the general public on October 16, 2014, as a free update through the Mac App Store worldwide.
It featured a major overhaul of user interface, replaced skeuomorphism with flat graphic design and blurred translucency effects, following the aesthetic introduced with iOS 7.
It also allowed websites to support Apple Pay as a method of transferring payment, using either a nearby iOS device or Touch ID to authenticate.
It also features Sidecar, which allows the user to use an iPad as a second screen for their computer, or even simulate a graphics tablet with an Apple Pencil.
[80][81] Big Sur introduced Rosetta 2 to allow 64-bit Intel applications to run on Apple silicon Macs.
