Before jumping into the history of Linux we must pass through UNIX.
History of UNIX :
It started in 1964 in New Jersey when some people of Bell Labs tried to create a multiuser operating system (OS), they worked on it till 1969, after facing lots of failures they withdraw the project.
Then a group of five people including Dennis Ritchie and Ken Thompson successfully created an operating system called UNICS(Uniplexed Information and Computing Service), better known as UNIX. They publish this OS as open-source(free to use and edit the codebase).
In 1975 a version of UNIX was released labeled "UNIX v6", it became very popular. Some companies tried to make a profit from it, so they made their own commercial version or flavor of UNIX :
- IBM - AIX
- Sun Solaris
- Mac OS
- HP UX
Why Linux was created?
Linux Torvalds is the creator of the Linux kernel. In simple words, Linus Torvald created Linux because he didn't have money to buy UNIX.
He was a student at the University of Helsinki. In early 1991 he decided to do a project on UNIX, but free versions of UNIX were too old and other commercials are too costly ($5000). So he thought of creating his own OS.
Does Linux is an exact copy of UNIX?
Actually not, let me clear this for you. For idea purpose, Linus did research on UNIX, but more than UNIX he did research on MINIX OS. And no, Linux is not an exact copy of UNIX.
What is MINIX?
MINIX was created by Andrew S. Tanenbaum on 1987. MINIX is a Unix-like operating system based on a microkernel architecture.
The main reason behind creating MINIX is to teach his students and the book he was writing Operating Systems Design and Implementation
Fact: MINIX is a text-oriented operating system with a kernel of less than 6,000 lines of code 😵
After Linux developed!
So finally Linux was released on September 17, 1991. Linus made it open source.
In between 1991 to 1995, Richard Stallman started a movement called the "Free Software Movement", and created GNU project (collection of free software).
Linux is a kernel and not an operating system and GNU is a collection of free software, these two project collabs give us "Linux" or "GNU/Linux" operating system. Some companies and open source communities adopt GNU/Linux codebase, did some modifications, and created their own version or distributions, eg:
- RHEL (Red hat)
- Fedora
- Debian
- Ubuntu
- CentOS
- Kali Linux
- others
Point to be Noted:
- Linux is a kernel, not OS.
- Linux is not a UNIX clone, it was written from scratch.
- A Linux distribution is the Linux kernel and a collection of software that together creates an OS.
Features or Linux or Why Linux is so popular?
Linux is so much popular that most IT companies ask their candidates that "Do they have knowledge or experience of Linux-based OS?".
Some points are mentioned below of the reason behind why it's so popular / Features :
- Open Source
- Lightweight
- Secure
- Multiuser - Multitask
- Simplified update for all installed software
- Multiple distributions ( RedHat, Debian, etc)