Detailed · 11 events
A History of Operating Systems
1960s
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 rewrite in the C language (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
Gary Kildall's disk operating system for the Intel 8080. Commercialised through Digital Research in the late 1970s, CP/M became the de facto standard OS of the 8-bit microcomputer market. When IBM went to pick an OS for the IBM PC in 1981, CP/M was its first stop; the talks failed, and the alternative—Microsoft's MS-DOS—became the standard of the PC-clone world. CP/M is therefore one of the great branch points in computing history.
1980s
Microsoft adapted 86-DOS (formerly QDOS), which it had bought from Seattle Computer Products, and shipped it as PC DOS 1.0 with the IBM PC. 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.
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.
Microsoft's first graphical environment, running on top of MS-DOS. Tiled (not overlapping) windows, limited colour, and a thin application library—the reviews were unkind, but it was the start of Microsoft's decade of sustained GUI investment that led to Windows 95. It lagged the Macintosh by one year and ten months.
1990s
Overlapping windows, the Program Manager, virtual-memory management, full VGA colour. Diverging from the OS/2 line being co-developed with IBM, Windows 3.0 went to market as an independent DOS-hosted GUI and sold two million copies in six months. It was the turning point at which Microsoft broke from the IBM joint venture and set out on its own.
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 ran to about 10,000 lines, indebted to Minix but written as an independent kernel. Released under the GPL in 1992, it grew through contributions from developers worldwide; by 2026, Linux is the kernel at the core of most of the world's servers, smartphones, and supercomputers.
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. Seven million copies were sold in the first week.
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, and laid the foundation for the Aqua UI, iOS, and modern macOS.
The first shipping device—HTC Dream, sold in the US as the T-Mobile G1—running the OS Google had acquired with the 2005 purchase of Android Inc. A Linux kernel, a Java VM (later replaced by the Android Runtime), and a custom UI stack: Google's strategy of supplying an open-source smartphone OS was the inverse of Apple's, and over the next decade and a half grew into an ecosystem accounting for more than 70% of the world's smartphones.
Unveiled by Steve Jobs at Macworld in January 2007, the iPhone went on sale in the United States on June 29 of the same year. By dropping the physical keyboard in favour of capacitive multi-touch and putting an OS X-derived operating system on a phone, the device rewrote the grammar of the product category that would later be called the smartphone.