Title: Unix/Linux History
Course: CIS 121: Linux/UNIX I: Fundamentals ~ For IGNITE Review > Section: Learning Modules

All modern operating systems have their roots in 1969 when Dennis Ritchie and Ken Thompson developed the C language and the Unix operating system at AT&T Bell Labs. They shared their source code (yes, there was Open Source back in the 1970s) with the rest of the world, including the "hippies" in Berkeley California. By 1975, when AT&T started selling Unix commercially, about half of the source code was written by others. The "hippies" were not happy that a commercial company sold software that they had written; the resulting (legal) battle ended in the creation of two versions of Unix in the 1970s; the official AT&T Unix, and the free BSD Unix.

In the 1980s, many companies started developing their own Unix: IBM created AIX, Sun, SunOS (later Solaris), HP HP-UX and about a dozen other companies did the same. The result was a mess of Unix dialects and a dozen different ways to do the same thing. This gave rise to the real root of Linux - Richard Stallman aimed to end this era of Unix separation by starting the GNU project (GNU is Not Unix). His goal was to make an operating system that was freely available to everyone, and where everyone could work together (like in the 1970s). Many of the command line tools that used today on Linux or Solaris are GNU tools.

The evolution continued in the 1990's when Linus Torvalds bought a 386 computer and wrote a brand new POSIX compliant kernel. He put the source code online, thinking it would never support anything but 386 hardware. Many people embraced the combination of this kernel with the GNU tools, and the rest, as they say, is history.

Today more than 90% of supercomputers (including the complete top 10), more than half of all smartphones, many millions of desktop computers, around 70% of all web servers, a large number of tablet computers, and several appliances (dvdplayers, washing machines, dsl modems, routers, ...) run Linux. It is by far the most commonly used operating system in the world.

Linux kernel version 3.2 was released in January 2012. Its source code grew by almost 200,000 lines (compared to version 3.1) thanks to contributions of over 4,000 developers paid by around 200 commercial companies including Red Hat, Intel, Broadcom, Texas Instruments, IBM, Novell, Qualcomm, Samsung, Nokia, Oracle, Google and even Microsoft.

Source: Cobbaut, P. (2013). Linux fundmentals. Retrieved from http://linux-training.be/