by Isaac Msiska

I used to ask myself the same question a couple of years back when I was just getting myself acquainted with the world of tech and computers. Whenever I heard the words ‘Linux’ and ‘Unix’ I would tell myself that these terms are just one and the same and with that, I would switch them around and use them interchangeably. So, I would proudly transpose Unix with Linux and the other way round. It took me quite a while to realize that I had everything upside down. 

Unix is not Linux and Linux cannot be Unix. Did I shock you? I bet I did. 

Well, if you belong to the large margin of individuals who still believed that Unix and Linux are geek phrases used to identify the same thing, I will take through the nitty-gritty that will prove you otherwise. I will break down the differences between Unix and Linux to give you a clear understanding of these leading Operating Systems (OS). 

Hello Unix

To draw a clear distinction between Linux and Unix, we need to stroll down the memory lane and rummage through the archives for a complete backstory of these two rivals. Let’s start with the mother, Unix. Unix’s birthplace is AT&T Bell Laboratory’s headquarters in New Jersey. It all started in 1969 with Ken Thompson, who was working as a researcher on a time-sharing Operating System known as the Multiplexed Information and Computing Service (Multics) project. By the way, time-sharing is a computer strategy that allows many people at different computer terminals to simultaneously use a specific computer system. Multics was supposed to be a revolutionary computer system but its complexity caused AT&T to exit the project. Learning from the challenges encountered with Multics, Ken Thompson joined by his fellow computer nerd, Dennis Ritchie, started developing a simpler, portable, and less complex Operating System. The new system was named UNICS (short for Uniplexed Operating and Computer System). From there on, the name kind of morphed into present-day Unix. 

Along came Linux… 

In the 1970s Unix’s popularity boomed. The OS was widely adopted and deployed across multiple IT sectors in universities and private corporations. Trouble began in 1979 when AT&T Bell revised its policies and barred universities from using the Unix source code for studies. Probably bored with this, Andrew Tanenbaum, a computer science professor at Vrije Universiteit in Amsterdam developed a Unix look-alike (a Unix clone), called Minix which was meant for use in his class. However, Minix had its own set of drawbacks – modification and redistribution were restricted. So, in 1991, Linus Torvalds, a Finnish Computer Engineering student, used Minix as a foundation to create a free re-distributable open-source Operating System which became what is now known as Linux. 

Now the differences

Enough with the history lesson. What makes Unix completely different from Linux is not just the historical variation – there are other stark distinctions that make the two stand on opposite ends of the road. Let us dismantle Unix and Linux to explore four major differences. 

Open-source vs licensed: 

Linux is open-source, meaning that the source code for the Operating System is free for re-distribution and modification. It is also developed by a vibrant community of programmers who work to advance the OS. Unix is not public, neither is it free for distribution. Specific source code of Unix may be bought under a proprietary commercial license but modification is not allowed. 

Downloadable vs hardware coded: 

Linux is available as downloadable and executable software which can then be independently installed on computers. Examples are ubuntu and Linux Mint. Unix is not downloadable. The Unix OS ships with the hardware essentially eliminating the chances of independent installation. Examples include MacOS.  And unlike Linux, Unix can only be installed in selected Central Processing Units (CPUs).  

Usage

Unix’s usage is limited. Unix was specifically built for use in servers, workstations, and high-end computers. On the other hand, Linux is flexible and can be used by everyone and everywhere from home computers, mainframes and smartphones to tablets and servers. 

Kernel vs fully-fledged

Unix is a fully functional Operating System while Linux is just a kernel – a portion of the OS. Linux depends on various Graphical User Interfaces (GUIs) and applications from different sources to become a working Operating System. Unix is complete on its own and ships with its own programs. 

Case in point

Linux is a Unix clone, a look-alike. It is an OS that closely resembles Unix and designed to mimic some of the concepts in Unix. It is not Unix. Neither is Unix Linux.