Still, there were many points at which things could have gone awry and decimated the company.
[For a more visual timeline of OS X, check out our slideshow, The evolution of Mac OS X.]
The road to OS X's initial release was a very bumpy one. Even before there was any thought of Apple buying NeXT, thus returning its CEO, Steve Jobs, to the company, Apple executives faced challenges with what was then thought of as the classic Mac OS.
The original Mac OS may have been revolutionary when it was unveiled in 1984, but it wasn't designed with many features that modern operating systems would need. Initially, it offered no ability to multitask, although "cooperative multitasking" could allow a single app to monopolize the processor. There was no protected memory, meaning that if one app crashed it would likely take others down with it and potentially the entire OS. And aside from a little-known product called At Ease aimed primarily at education, it offered no support for multiple user logins.
All these challenges were becoming obvious by the early 1990s, prompting Apple to devise a strategy to create a next-generation OS. The primary focus was an internal project called Copland, announced in 1994. After significant delays, Apple's then CTO Ellen Hancock and CEO Gil Amelio froze development of Copland as a successor OS in 1996. Several parts of the project were pushed into the development of Mac OS, but they were more useful add-ons than core architectural changes.
Apple then began looking for other companies that could supply a base for a future Mac OS. Multiple options were reportedly considered, including Windows NT, Sun's Solaris and a nascent computing platform called BeOS -- the last one created by Be, a company founded by former Apple exec Jean Louis Gasse. Be seemed the clear favorite, but as negotiations dragged on, Apple got a call from NeXT. Jobs returned to the Apple campus for the first time in over a decade and presented NeXT's OS as a fully functional and modern platform that was years ahead of BeOS.
In what struck many as a surprise move, Apple acquired NeXT and the real journey to OS X began. (For an excellent retelling of this saga, check out Owen Linzmayer's Apple Confidential.)
Apple faced three major challenges in transitioning its core product line to a completely new OS, whether it was developed internally or by acquisition. The first was getting the new OS out the door quickly. Apple was in dire straits in the mid-'90s and was losing market share to Microsoft. It needed a quick win. That led to the second challenge: Keeping developers engaged enough to write or rewrite apps for a new platform, something made more challenging by Copland's delays and cancellation. Finally, Apple needed to convince its user base to adopt the new OS.
Appealing to Apple users was crucial, as attracting new users would likely get harder over time. Those die-hards also had different wants, needs and agendas.
The main reason Apple needed this buy-in was that OS X was designed to be the single future OS. Although Apple didn't need everyone to migrate on day one, it did need for everyone to do so eventually.
The initial effort was called Rhapsody; it involved an environment that ran the new OS (known as the Yellow Box) and the ability to run existing Mac apps (the Blue Box). Apple released two developer previews of Rhapsody, but after Jobs retook the reins of the company, the new OS was rebranded as Mac OS X (later OS X). The Blue Box concept survived as the "Classic environment" in early OS X releases; it essentially ran a version of Mac OS 9 inside OS X as though it were an app or OS X process.
Before OS X arrived in consumer form, the first beta version of a server OS for education and enterprise environments called Mac OS X Server 1.0 was released. It supported services like file sharing, Mac management and booting from a shared network image rather than a physical drive (useful in education and kiosk environments). This initial release wasn't like any later version of OS X (or OS X Server). It was essentially a version of Rhapsody and was very much a mashup of NeXT's OPENSTEP and Mac OS 8.
In the fall of 2000, the public got its first look at the consumer version of OS X -- as a $29.95 public beta. Although Apple has a penchant for presuming it knows what users want before they do, the company made an exception to that rule in this case and feedback about the beta did inspire changes in some of OS X's user experience. The most notable tweak was the continued existence of the Apple menu, which wasn't present in the beta.
Mac OS 9, released while OS X was already in development, served as an important bridge between the two operating systems. While it didn't introduce any of the core architectural changes Apple needed, it did add support for multiple user logins, including network accounts; a basic level of Mac management; and the underpinnings needed for it to function as an OS X process as part of the Classic environment.
The first commercial release of OS X, code-named Cheetah, went on sale for $129. It wasn't an immediate hit. There were issues with performance, many users experienced kernel panics that could require a forced restart, features like burning CDs and DVDs weren't supported and there was a dearth of available printer drivers.
Simply put, Cheetah didn't seem ready for prime time.
Complicating the matter was a lack of native apps beyond those bundled with the new OS. Because launching the Classic environment essentially fired up Mac OS 9 after OS X had already booted, many users simply opted to boot into Mac OS 9 to use the majority of their apps.
The situation improved that fall with the release of Puma (OS X 10.1). Puma didn't add a huge number of features, but it did improve performance and stability. The features it did roll out, however, were significant to developing confidence in OS X: CD and DVD burning, DVD playback, drivers for 200 printers, and the Image Capture utility for accessing digital cameras and scanners. Apple released Puma free of charge to Cheetah users and offered the upgrade through its traditional sales channels as well as in its new retail stores, where people could get help with the transition from Mac OS 9 to OS X.
Puma's ability to rectify Cheetah's limitations was important, given that early in 2002 Apple announced all new Macs would ship with OS X pre-installed as the default operating system. Although this crop of Macs could still boot into Mac OS 9, it was clear that Mac OS 9 was on its way out.
Jaguar, released in August 2002, was the third version of OS X and the first that felt truly feature complete and ready for use as a primary OS. (It was also the first time Apple branded OS X using its internal codename). Jaguar incorporated a number of notable new features and built-in apps that delivered value not available in Mac OS 9. Its popularity compared to its predecessors was also boosted by the fact that new Macs would boot into OS X by default, and that a large swath of developers had begun to release OS X native apps.
Two of the most notable features in Jaguar related to networking. The first was Rendezvous (later renamed Bonjour), which allowed Macs to automatically detect resources like shared printers and scanners, file servers and other Macs offering services on a local network. The second was built-in support for Windows file and printer sharing. This made integrating Macs into Windows environments or a mixed Mac/PC home environment much easier.
Jaguar also enhanced the Mac's file system and graphics capabilities, introduced a more advanced email client and a native instant messaging client (iChat), and included Universal Access features for users with disabilities. Additional software released around Jaguar included Apple's Safari browser, iCal (later renamed Calendar), and iSync, which allowed syncing of calendar and contact data across multiple Macs and other devices like iPods, PDAs and some cell phones.
Released in October 2003, Panther marked a couple of important milestones for OS X, including the first major change to the user interface -- the brushed metal look that would dominate the UI for more than a decade -- as well as redesigned Finder windows that include the sidebar still in use today.
Probably the most significant change in Panther was the move away from proprietary directories for storing user, group and computer information. Panther and Panther Server introduced support for a new network directory system, Open Directory, built on open standards including LDAP and Kerberos. Open Directory was appropriate for network environments and, because it was based on open standards, Macs could integrate directly with Microsoft's Active Directory.
That meant that for the first time a user could log into any Mac or PC in a company using the same set of credentials and have access to the same set of network resources.
Apple also ramped up security with Panther by introducing FileVault to automatically encrypt and decrypt a user's home directory on the fly. Other notable additions included Fast User switching, allowing multiple users to be logged in at one time; Expose for easily managing open apps and windows; audio and video chat in iChat AV; and the introduction of Apple's Xcode developer environment, which is still in use today.
Tiger was released a year and half after Panther, in the spring of 2005. Like its immediate predecessors, it boasted new features and apps that remain with us now: Spotlight search; easy scripting with Automator; VoiceOver for reading text; the first iteration of Parental Controls; and Dashboard, which allowed for dynamic HTML widgets to display data in an overlay of the desktop for easy access. (That feature was later replaced by the Notification Center widgets in Yosemite.)
The most significant place Tiger plays in Mac history, however, came several months after its initial release. It was the first commercial version of OS X to run on Macs with Intel processors, the first of which -- the MacBook Pro and first Intel iMac -- stunned the world when they were unveiled in January 2006.
Although Tiger was the first commercial version of OS X to run on Intel processors, Apple had actually been hedging its bets for years in case it ever needed to replace the PowerPC chips that had powered Macs since the early '90s; the company had reportedly produced an Intel version of every OS X release. The move away from the old Classic environment and Mac OS 9 apps made for a cleaner move to Intel when it was needed.
The transition to Intel chips was about more than having an appropriate version of OS X ready to go. As with the transition from the classic Mac OS to OS X, Apple needed developer support. Also like that transition, it meant that developers would need to port their apps. Apple planned well for this as it developed and refined the OS X APIs, somewhat minimizing the work needed by developers to make the switch. The Mac by this point had also become a surer bet for developers than when OS X was being developed eight years earlier.
One difference, however, was that Apple didn't have to worry about winning over users. OS X on Intel looked and felt exactly the same as on a PowerPC. Although Apple did need to provide a way to run PowerPC apps for a time, it did so with an emulation engine called Rosetta that ran transparently in the background. From a user perspective, PowerPC apps simply worked, though they did run a bit slower than Intel apps.
The transition also allowed Apple to attract new users since Intel Macs could also run Windows. This was done either through Apple's Boot Camp, which allows a user to boot into either OS X or Windows, or through virtualization tools like Parallels Desktop, VMware Fusion, and VirtualBox, all of which allow Windows (and Windows apps) to run alongside OS X.
The seamlessness of this transition was matched by how fast it occurred. Apple introduced the first Intel Macs in January 2006 and finished moving its complete Mac lineup to Intel processors in just eight months.
Without a doubt, 2007's Leopard release was the most feature-packed version of OS X ever, boasting more than 300 new features big and small as well as several significant interface tweaks such as the 3D shelf-like Dock. A full list of these features goes well beyond the scope of this retrospective, but here are some highlights.
Back to My Mac offered easy remote access to one's Mac; the Dock gained the ability to preview folder contents using Stacks; iChat gained support for projecting content to other users and remote screen sharing; QuickLook made it easy to preview documents without opening them; Spaces offered users virtual desktops to help organize onscreen content and minimize clutter; Time Machine made backups (and restoring items from backups) incredibly easy; and an application firewall, along with support for digitally signed applications and application sandboxing, improved security.
Leopard also furthered Apple's enterprise goals by supporting access to Microsoft Exchange in its native email, contacts and calendar tools.
Leopard Server included several important new features, particularly for small and mid-size businesses. It offered a simplified setup process and tools designed for ordinary users rather than IT pros. It also included easy-to-manage services for features like email, internal messaging, wikis and shared contacts/calendars. Leopard Server also became easier to integrate as a departmental solution in larger enterprises with an Active Directory infrastructure.
It's worth noting that Leopard shipped later than expected, in October 2007, largely because resources had been pulled from the OS X development team to help finalize development of something new from Apple: The original iPhone.
In contrast to its feature-packed predecessor, Snow Leopard, released in August 2009, focused almost entirely on improving performance. It was the least feature-filled OS X release since Puma in 2001. Snow Leopard was significant for two reasons beyond those under-the-hood updates: it was the first version of OS X not to run on PowerPC hardware and it was the first version to support the Mac App Store, which was introduced early the following year.
One of the biggest themes of Lion, which arrived in the summer of 2011, and its successor in 2012, Mountain Lion, was the incorporation of iOS features, apps and user experience into OS X itself. Beginning with Lion, OS X has received a major update on a annual release cycle like iOS. Also noteworthy is that Lion was the last release of OS X that Apple charged money for -- all subsequent releases have been free upgrades. (Even then, Lion was a bargain compared to past upgrades as it maintained Snow Leopard's $29.99 price.)
Features built into Lion from iOS included a revamped Address Book app with an iPad-like interface; support for FaceTime calls; iOS-style autocorrect; support for automatic saving of application states and resuming of states on relaunch; Emoji support; a focus on full-screen apps; and multitouch gestures on Apple trackpads and Magic Mouse.
Under the hood, Lion also began to use iOS-style configuration profiles and Apple's MDM framework for managing Macs in enterprise and education environments. To this end, OS X Server got a Profile Manager tool to manage Macs and iOS devices as Apple began deprecating its earlier Mac management approaches. The move also opened Mac management up to a wider array of vendors as many MDM/EMM vendors could now offer Mac as well as iOS management capabilities -- a move that Microsoft later made in Windows 10.
In an effort to reposition OS X Server for the small- to mid-sized business market, Apple offered it as an optional add-on to Lion rather than selling it at a significant cost. Previous editions had cost $499 for a 10-client license and $999 for unlimited use.
Lion also introduced more security functionality, including extending FileVault to offer whole disk encryption and extending support for address space layout randomization.
To make file sharing easier, Lion also boasted AirDrop, which allows nearby Macs to share data over Wi-Fi even if they are not connected to the same (or any) Wi-Fi network.
Mountain Lion continued to make the Mac more iOS-like with the addition of an OS X version of the iOS Notification Center; an independent Notes app; revamped/renamed Messages, Contacts and Calendar apps; the introduction of Game Center support; and unifying OS and application updates into an automatic feature of the Mac app store.
Other notable Mountain Lion additions included AirPlay Mirroring, which allows an Apple TV to mirror a Mac's primary display; support for Chinese social media and sharing services; support for VIP users in Mail; and the GateKeeper security feature for verifying the reputation of apps acquired from outside the Mac App Store based on an Apple-signed developer certificate. Power Nap was introduced to allow some Mac models to sync content while sleeping.
Mavericks, released in 2013, became the first version of OS X to break with the tradition of naming releases after big cats -- at least in part because Apple was beginning to run out of options and there were repeated jokes that the company might have to resort to domestic cat breeds like OS X Tabby. Future versions are named for iconic locations in Apple's home state of California.
Beyond the name change, Mavericks introduced a range of new features, some completely new, others also borrowed from iOS.
It introduced an OS X version of Apple Maps, complete with integration into other apps and services -- most notably Calendar, with reminders about when to leave for events based on location and traffic/weather conditions -- as well as the ability to send map information to an iPhone for on-the-go use. Similarly, the iBooks app made the leap from iOS to OS X. Notification Center gained several new features, including quick-reply options for emails and messages, the ability to view notifications from the lock screen and support for notifications from websites.
Mavericks also significantly expanded the Accessibility options for OS X with new system control and display options for users with disabilities.
One particularly useful feature was an expansion of AirPlay support -- introduced in Mountain Lion -- that could turn an HDTV connected to Apple TV into a full-fledged secondary wireless display in addition to simply mirroring the primary display. Another was the introduction of iCloud Keychain for securely syncing passwords and other confidential information among Apple devices.
For enterprise and education, Mavericks simplified the process of enrolling Macs into a management solution using Apple's MDM protocol; added support for an application-layer VPN to ensure that only work-related apps routed traffic through the connection; bolstered FileVault key recovery options; and introduced more advanced passcode policies. Other security additions included expanded use of app and plug-in sandboxing and FIPS 140-2 certification.
The most dramatic thing about 2014's Yosemite was that it was the first major overhaul of OS X's appearance since Apple adopted the brushed-metal look in 2003's OS X Panther. The new "flat" interface mirrored the design language Apple adopted in iOS 7.
Yosemite's new look may have been the first thing anyone noticed about it, but the release also included significant additions that pointed to Apple's vision of desktop and mobile computing going forward.
The first major addition was Continuity, a collection of features that integrated OS X and iOS more tightly than ever before. The biggest of these features, Handoff, allows a user to begin a task on one device and automatically continue that task on another. The feature works with a range of apps including Mail, Notes, Reminders and Maps. Continuity also made it possible for any Apple device to make and receive calls through a user's iPhone (and to hand off those calls to the iPhone) and made tethering a Mac (or iPad) to an iPhone or cellular iPad for Internet easy and automatic; it even allows a tethered device's battery to display on the Mac.
Continuity's feature set alone is impressive, but it also points to Apple's computing vision. Although the company is committed to integrating its platforms and sharing functionality, Apple has been firmly committing to keeping them as separate platforms rather than trying to merge OS X and iOS. This contrasts with Microsoft's Continuum effort to create a unified Windows platform and experience across all the devices that it makes or supports.
Notification Center also received a major boost with support for third-part widgets and a Today view similar to that of iOS. Likewise, AirDrop got a notable upgrade in the ability to share content with nearby iOS devices as well as Macs.
Spotlight saw a major update, arguably the most significant since it was introduced. In Yosemite, it took center stage for searching content on a Mac, on the Web, for local businesses and for movie times via Maps, iBooks, iTunes, the Mac App Store, Wikipedia and various news sources.
The next biggest innovation introduced in Yosemite was the new Swift programming language that could be used to write apps for OS X and iOS. Swift is a modern and relatively easy to learn language for novices that set the stage for the future of development across all of Apple's lineup.
Finally, Yosemite was the first OS X version to be offered as a public beta since 2000's pre-release beta of OS X. Apple has continued to offer public betas of OS X as well as iOS releases.
The most recent version of OS X, El Capitan, was released last fall and focused largely on under-the-hood improvements to performance, stability and security. El Capitan features the Metal graphics API and several other performance enhancements. It also introduced System Integrity Protection, a feature that secures many system processes, files and folders against changes even if those changes were made using root privileges.
Although El Capitan focused primarily on unseen advances, it did introduce several new features, including a split-screen view similar to that on recent iPads, for viewing two full-screen apps side by side; improved window management in Mission Control; the ability to easily locate the cursor quickly by moving the mouse to enlarge it; better natural language search in Spotlight; a much improved Notes app that matches the functionality of Notes in iOS 9; public transit directions in Maps (though only for a limited number of cities); and a new system-wide font called San Francisco.
Looking back, it's easy to forget what a gamble OS X represented for Apple in the beginning, but the gamble clearly paid off big time. OS X has stood the test of time. It provided Apple and its fans something to hold onto while the company began building iconic products -- the iPod, the iTunes Store, the iPhone, and the iPad - that would revolutionize Apple (and much of the larger technology landscape). OS X helped to propel the Mac to record sales in fiscal 2015, and growth has continued since then even as the PC market overall has continued to contract. It is without a doubt a major success story.
OS X also reflects the company it helped Apple to become. It has always been nimble, forward looking and willing to jettison technologies when required rather than becoming bloated by trying to hold onto years or decades of backwards compatibility. That ability, and Apple's care with its development, have made OS X a strong OS with remarkable staying power after 15 years.
OS X helped transform Apple -- and thus transform much of the technology world. Happy birthday OS X. Here's to another 15 years.
Next: Macs dent the enterprise, but not by much