A Brief History of Unix and How did Linux came into being
What is Unix?
Unix is a family of operating systems whose origins go back to the Research Unix operating systems of the AT&T Bell Labs from the early 1970s.
The Beginnings
Firstly, Unix is an old operating system that has its origins in the 1960s, during the era of mainframe computers. In collaboration with General Electric, AT&T and later Honeywell, MIT developed an early time-sharing operating system called Multics, which stood for Multiplexed Information and Computing Service. Despite being an ambitious project, Multics was not successful due to its complexity. Ken Thompson and Dennis Ritchie, developers at AT&T Bell Labs, identified this issue and sought to develop their operating system to address these problems. They named their new operating system Unics, which later became Unix, based on their idea of “Keep it Simple Stupid”. It is worth noting that the name Unix is a pun on Multics.
The first version of Research Unix was released in 1971, running on the DEC’s PDP-11 minicomputer. Due to legal issues, AT&T was unable to sell Unix as a commercial product, and instead made it available through a relaxed non-commercial license to research institutes and universities. This led to the rapid popularity of Unix in academic circles.
P.S. Multics still exists today, and you can check it out as a curiosity by following this link: https://www.multicians.org/.
The beginnings of the BSD Unix line
One of the initial versions of Unix was created at Berkeley University and named Berkeley Software Distribution. Bill Joy, a computer engineer who is best known as the inventor of Vi Text Editor and the founder of Sun Microsystems, was among the prominent individuals who contributed to the early development of BSD.
In the 1990s, the BSD distribution evolved and became entirely open source under the name 386BSD. Although 386BSD faced legal challenges initially, these issues were eventually resolved, and all closed source code was eliminated. Most current BSD operating systems are descendants of 386BSD, as well as another branch known as 4.3 BSD.
UNIX System V and the rise of commercial Unix Operating Systems
By 1983, due to the 1982 Antitrust lawsuit, AT&T had become a significantly smaller company and had to relinquish most of its telecommunications business to smaller regional bell companies. As a result, AT&T began developing and marketing one of the first commercial versions of Unix, called UNIX System III. Many commercial Unix operating systems during the 1980s were descendants of Unix System III.
Later on, in 1988, AT&T and Sun Microsystems collaborated to produce SVR4, which integrated the features of both SVR3 and BSD Unix. This was a significant milestone, and most commercial Unix operating systems switched to SVR4.
Microsoft and its distribution of Unix
Yes, Microsoft was also involved in this market with its version of Unix known as Xenix. It was initially based on Research Unix 7, but later versions were derived from Unix System III and UnixVR2. Xenix was a 16-bit operating system designed for IBM PCs and clones, with limited connectivity except for the serial port.
Microsoft marketed Xenix throughout the 1980s, but eventually, after the emergence of Unix V, the company realized that it could not compete in the market and abandoned the operating system. Instead, Microsoft shifted its focus to OS/2 and later Windows NT. Microsoft sold Xenix to one of its distributors, SCO, and Xenix eventually evolved into SCO OpenServer.
In the meantime, AT&T sold Unix System V to Novell and withdrew from the Unix market altogether. Unix System V eventually became Novell UnixWare, but Novell also left the Unix market and sold UnixWare to SCO.
The rise of open-source movements
During the 1980s, there was a thriving hacking culture in universities centered around the Unix operating system and the free distribution of code. However, this culture dissipated with the emergence of commercial Unix operating systems, which prompted the creation of various open-source movements.
One of the most notable of these movements was the GNU Project, spearheaded by Richard Stallman from MIT.
The rise of the open-source Unix-like operating systems
In the early 1990s, the GNU Project had achieved nearly all of its objectives of creating a free and open-source alternative to commercial Unix operating systems, but it still lacked a kernel. Around this time, a software developer from Finland, named Linus Torvalds, created his own open-source Unix-like operating system called Linux. The development of Linux was influenced by another academic Unix-like operating system called Minix.
Initially, Linux was only a kernel, so to address the need for user-land utilities, Linus Torvalds utilized the GNU utilities and the GCC compiler, resulting in the creation of GNU/Linux.
Meanwhile, the Computer Systems Research Group at Berkeley University faced financial difficulties and was in danger of shutting down. To ensure the future of BSD distributions, its developers decided to make it open source. However, they faced a lawsuit because the BSD operating systems still contained the original Unix code from the 1980s. By 1994, the case against BSD had been settled, and most of the closed-source code was removed, resulting in the birth of modern BSD operating systems.
The demise of the Unix workstation market
In the mid-1990s, advancements in technology led to a decreased need for specialized computers with proprietary Unix operating systems. As a result, generic Pentium-based computers with open-source operating systems such as Linux and the BSDs became a viable alternative for many users. This shift in the industry led to the collapse of the Unix workstation market, with each proprietary system gradually losing its place. The final one to fall was Sun Microsystems, which was acquired by Oracle in 2010.
The survivors
Today, only a handful of proprietary Unix operating systems are still in use, including IBM’s AIX, HP-UX, Oracle’s Solaris, and the modern Mac OS, which originated from Steve Jobs’ NeXTSTEP. The Illumos operating system, derived from the now-defunct OpenSolaris project, is the only open-source Unix operating system still actively developed and used. However, the legacy of Unix continues to live on in modern operating systems, such as Linux and the BSDs, which were inspired by Unix and continue to be developed and improved upon by a large community of developers and users.
