What is Linux?
Most people think that Linux is an OS, but it is actually not. Linux itself doesn’t form an OS. Linux is nothing but a Kernel.
Kernel is a large code of millions of lines, which forms the core of any operating system. It can be considered as a resource manager of an operating system. User applications can communicate with the hardware only through the kernel. It is the kernel which keeps the OS up and running.
Linux kernel based operating systems are called Linux OS, like redhat, Linux mint, Ubuntu, centos etc.
History of Linux
UNIX is considered as the very first operating system of all its characteristics. Before UNIX there was no operating system concept. UNIX was developed by the employees of AT&T Bell Laboratories) in 1969
UNIX was not a free OS; also the OS was not available for common users. Actually at that time there was no personal computer concept. So the operating system was mainly used in mainframe computers and for research purposes.
There was a research student’s version of UNIX called Minix released in the year 1987. The source code of the Minix was available, but modifications were not allowed.
Linus Torvalds from the University of Helsinki was doing a personal project in which he tried to modify the kernel of Minix and develop a new one of his own. He was using Minix since his school days. He posted on the internet that he is trying to develop the kernel for a new operating system. So many brains around globe respond to this and contribute their code. Linus Torvalds coordinate all these and formed Linux kernel in the year 1991.
The Free Software Foundation (FSF) started by Richard Stallman in the year 1983, was running a project called GNU (Gnu Not Unix). They had the entire user interface ready, but their kernel was a complete failure. They used the Linux kernel developed by Linus Torvalds for their GNU project and formed GNU/Linux.
FSF licensed the operating system GNU/Linux under GPL (General Public License) in the year 1992. The OS is available for free. It was open source, which means the source code is available. Anyone can modify the source code and develop their version of OS. But GPL doesn’t allow common people to distribute their modified Linux OS; all the modified versions should be submitted back to the FSF.
History of Linux