Detailed · 18 events
A History of Operating Systems
1960s
- EVT.001T1Engelbart's Demo — Ninety Minutes of Interactive ComputingA History of the Internet and the WebA General History of Information TechnologyRead more →
Unknown (via Jargon File, Wikimedia Commons) · Public Domain · Commons ↗ Having left the Multics project, Ken Thompson at AT&T Bell Labs began writing a small timesharing system on an idle PDP-7. Initially an experiment for one user, it gained a second when Dennis Ritchie joined; in 1970 it was named UNICS (later UNIX). Its 1973 rewrite in the C language (designed in 1972) gave it portability, and the operating-system lineage that followed has dominated the next half-century. Linux, macOS, Android, and iOS all descend from it.
1970s
- EVT.003T1The Xerox Alto — The Machine That Was Never SoldA History of Semiconductors and HardwareA General History of Information TechnologyRead more →
Bill Bradford · CC BY 2.0 · Commons ↗ Gary Kildall's disk operating system for the Intel 8080; the first working prototype ran in 1974 in Pacific Grove, California. Kildall and his wife and business partner Dorothy McEwen commercialised it through Digital Research (first called Intergalactic Digital Research), and CP/M became the de facto standard OS of the 8-bit microcomputer market. When IBM went looking for an operating system for the IBM PC in 1980, its first stop was Microsoft, and it was Bill Gates who sent the team on to Digital Research—the familiar telling, that IBM came to buy CP/M first, has the order backwards. The DRI talks collapsed (accounts disagree on whether the sticking point was the non-disclosure agreement, an outright purchase versus per-copy royalties, or the delivery schedule), and IBM instead took 86-DOS, written at Seattle Computer Products to implement CP/M's programming interface and bought by Microsoft, which shipped it as PC DOS and MS-DOS. On the IBM PC the two were sold side by side at US$240 for CP/M-86 against US$40 for PC DOS, and the price gap settled the matter. CP/M is one of the great branch points in computing history.
Questions this page answers
- Did IBM go to Digital Research first for the IBM PC's operating system?
- No. IBM's first stop was Microsoft, and it was Bill Gates who sent the team on to Digital Research. The familiar telling has the order backwards.
- Why did PC DOS win over CP/M-86 on the IBM PC?
- Price settled it. The two were sold side by side at US$240 for CP/M-86 against US$40 for PC DOS.
1980s
The wub (Wikimedia Commons) · CC BY-SA 4.0 · Commons ↗ IBM announced the Personal Computer on 12 August 1981, with first deliveries scheduled for that October. Microsoft adapted 86-DOS (formerly QDOS), whose rights it had bought outright from Seattle Computer Products the month before, and it shipped with the machine as PC DOS 1.0. Crucially, Microsoft retained the right to sell the same software, as MS-DOS, to any other compatible-machine manufacturer. Bill Gates' licensing strategy here produced the next fifteen years of PC OS dominance.
Bernard Gotfryd (Library of Congress, Prints & Photographs Division; edit by Commons user W.carter) · Public domain · Commons ↗ Apple introduced the Macintosh, bringing the graphical user interface invented at Xerox PARC—windows, icons, mouse—to a US$2,495 mass-market price. After the commercial failure of the more expensive Lisa the year before, Apple deliberately moved the balance of simplicity versus extensibility hard toward the former. The Ridley Scott Super Bowl ad introducing it has its own place in television history.
Rama & Musée Bolo · CC BY-SA 2.0 FR · Commons ↗ Microsoft's first graphical environment, running on top of MS-DOS. It was announced in November 1983 but did not ship until 20 November 1985—two years of slippage that earned it the label "vaporware." What reached the shelves was version 1.01, at $99. Tiled rather than overlapping windows (overlapping had to wait for Windows 2.0 in 1987), limited colour, and a thin application library—the reviews were unkind, and only about 500,000 copies had sold by April 1987. Even so, it was the start of Microsoft's decade of sustained GUI investment that led to Windows 95. It lagged the Macintosh, which went on sale on 24 January 1984, by one year and ten months.
1990s
Erkaha · CC BY-SA 4.0 · Commons ↗ Program Manager in place of the MS-DOS Executive, virtual-memory management via 386 enhanced mode, and redesigned icons and graphics (the bundled drivers gave up to 16 simultaneous colours on EGA, MCGA or VGA; 256 colours needed a capable adapter and the Palette Manager). The launch was staged at New York's City Center Theater for 6,000 people and relayed to seven North American and twelve international cities. Microsoft spent US$3 million on the event, which Bill Gates called the most extravagant, extensive and expensive software introduction ever. Diverging from the OS/2 line co-developed with IBM since 1985, Windows 3.0 went to market as an independent DOS-hosted GUI and sold two million copies in six months, and roughly ten million by the time Windows 3.1 arrived. That success recast the relationship between the two companies and became the turning point at which Microsoft broke from the IBM joint venture and set out on its own.
Lf Asia (Wikimedia Commons) · CC BY 3.0 · Commons ↗ Linus Torvalds, then a student at the University of Helsinki, posted to comp.os.minix: "I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu)." The first sources, version 0.01 released on 17 September, ran to 10,239 lines across 88 files — indebted to Minix but written as an independent kernel. The GPL took effect on 1 February 1992, and the kernel grew through contributions from developers worldwide; by 2026 Linux runs 61.7% of the websites whose OS is known, every machine on the TOP500 supercomputer list, and billions of Android devices.
Microsoft (Wikimedia Commons) · Public domain (logo, below threshold of originality) · Commons ↗ 32-bit preemptive multitasking, long file names, plug-and-play, and—most lastingly—the Start menu and taskbar. For many people the image of 'what a PC is' was set by this product. The campaign built around the Rolling Stones' 'Start Me Up' and the midnight launches drew lines around the block; the PC had become a household appliance. Microsoft's own figure was seven million copies in the first five weeks. The Japanese-language edition followed on 23 November 1995.
2000s
The release that replaced Apple's Classic Mac OS with the descendant of NeXTSTEP—the Mach-microkernel-plus-BSD UNIX environment Steve Jobs had developed at NeXT after leaving Apple in 1985, and brought back through Apple's 1996 acquisition of NeXT. It gave the Mac UNIX-derived robustness and process separation, arrived wearing the all-new Aqua interface, and laid the foundation for iOS and modern macOS.
- EVT.012T1The Original iPhone Goes on SaleA History of the iPhoneA General History of Information TechnologyA History of Mobile Phones and SmartphonesRead more →
Marcus Sümnick · CC BY 3.0 · Commons ↗ Two announcements landed on the same day: the Android 1.0 SDK, and the first handset built on it—the HTC Dream, sold in the US as the T-Mobile G1. The platform itself had been unveiled a year earlier, on 5 November 2007, when thirty-four companies formed the Open Handset Alliance; the phone itself did not reach shops until 22 October 2008, at $179 on a two-year contract. The OS descended from Android Inc., which Google had bought in 2005: a Linux kernel, the Dalvik VM (later replaced by the Android Runtime), and a custom UI stack. Supplying an open-source OS to handset makers was the inverse of Apple's approach, and over the next decade and a half it grew into an ecosystem running on roughly seven in ten of the world's smartphones.
Questions this page answers
- When was Android released?
- Three dates, and they are routinely conflated. The platform was unveiled on 5 November 2007 with the Open Handset Alliance; the Android 1.0 SDK and the HTC Dream were shown on 23 September 2008; the phone went on sale on 22 October 2008 at $179 on a two-year contract.
2020s
Microsoft (Wikimedia Commons) · Public domain (below threshold of originality; trademark applies) · Commons ↗ In 2015 a Microsoft employee said Windows 10 would be 'the last version of Windows' and the company declined to disown it; six years later Windows 11 arrived anyway—announced 24 June 2021, generally available 5 October 2021. The UI was refreshed: a centred Start menu, rounded windows, Snap Layouts, Android app support. Windows 11 made TPM 2.0 and Secure Boot hard requirements; an audit of some 30 million business devices found fewer than half met the CPU rule, leaving working PCs outside official support. Using hardware requirements to force upgrades proved contentious, and more than 40% of Windows PCs were still on Windows 10 after its 14 October 2025 end of support.
- EVT.015T1Rust Enters the Linux Kernel — A Second Language in MainlineA History of Programming LanguagesA History of Open Source and Free SoftwareRead more →
- EVT.016T1Copilot+ PC and Recall — On-Device AI and an Instant RetreatA History of MicrosoftRead more →
Apple Inc. (Wikimedia Commons) · Public domain (below threshold of originality; trademark applies) · Commons ↗ Apple released macOS 15 'Sequoia' alongside iOS 18 and iPadOS 18 — but the headline feature, Apple Intelligence, was not in 15.0. It arrived in stages: summarisation, rewriting and notification triage in 15.1 on 28 October 2024; Image Playground, Genmoji and ChatGPT integration in 15.2 on 11 December. The architecture paired a roughly three-billion-parameter on-device model with Apple-operated Private Cloud Compute servers. Eligibility was limited to Macs with M1 or later, iPads with A17 Pro or M1 or later, and iPhone 15 Pro or newer. The personal-context Siri shown at WWDC slipped repeatedly and was ultimately rebuilt in 2026 on Google's Gemini.
