Everything began in the 1970's when AT&T was allowed to license UNIX. Before that, UNIX was nearly for free and the source code was available to the public.
The GNU project
In order to create a free and open operating system, Richard Stallman founded the GNU project (GNU is a recursive acronym for "GNU's Not Unix"). The ideas of this "open" system were these:- The right to use the software for any purpose.
- The right to change the software for your needs.
- The right to share the changes you made with others.
After several years the system grew and you were able to run a GNU system on most of the UNIX Kernels. But unfortunately the GNU Kernel, called "hurd", was not able to replace the UNIX Kernel. Until now, there is no stable release of the hurd Kernel.
Then in 1991 Linus Torvalds wrote an own Kernel which was meant to be a terminal emulation to log into the university’s server. But his Kernel became more and more a "real" Kernel and it was more stable than GNUs "hurd" kernel.
Because of this, GNU was ported to the Linux kernel. The problem was now, that people were starting to call this operating system Linux. But Linux is only the Kernel, the operating system itself was still GNU. In the end you can say, that Linus "stole" all the fame and the name from Richard Stallmans GNU project! In the end some distributions renamed the system itself to "GNU/Linux" which is the "official" name for the operating system.
If you are a real Linux fan, you need to know Stallman, the origin of the GNU system and what he did.
Stallmans page: stallman.org/
Picture from: stallman.org/#photo_drawings