Unix began as a small, cheeky rebellion against an overgrown operating system
In the late 1960s Bell Labs researchers walked away from Multics, an ambitious time-sharing project with MIT and General Electric that had grown huge and unwieldy. Ken Thompson, Dennis Ritchie and a few colleagues started something smaller, with no official backing. In 1970 they named it Unics, a pun: uniplexed where Multics was multiplexed.
Brian Kernighan is generally credited with the joke name, though he admits nobody remembers how the spelling became UNIX. The first version was written in assembly language for a PDP-7 and could run only one task at a time. Multitasking, multiple users and portability came later. The crucial move came in 1973, when Version 4 was rewritten in the new C language, which then lacked features such as structures, making Thompson's job harder. The first port to entirely different hardware was done in 1977 at the University of Wollongong in Australia.
Its design became a philosophy. Rather than one big program doing everything, Unix supplied many small tools, each doing one job well, that could be chained together through pipes in the shell. Data lived in plain text, files sat in a single hierarchy, and even devices were treated as files. Kernighan and Rob Pike summed it up: the system's power lay more in how programs connected than in the programs themselves.
Compactness helped it spread. The complete Version 7 release of 1979, with every compiled program, all the source code and the documentation, took under 10 megabytes and fitted on one reel of nine-track tape. AT&T distributed it to universities, the first source licence going to the University of Illinois in 1975, and students learned computing on it. Commercial success then fractured it into rival flavours, from Berkeley's BSD to Sun's Solaris, IBM's AIX and Microsoft's Xenix, prompting the POSIX standard in 1988.
Its descendants run most of the modern world, from Apple's operating systems to Linux servers and supercomputers. In 2026 a forgotten tape holding Version 4 turned up at the University of Utah and was successfully read at the Computer History Museum.
Source: Unix
