Actually before Linux came to planet earth there was another kernel called
Unix and this was implemented in the 1960s and first released in 1970s. This was freely available and also because of it's portability Unix became a hit in the world of IT. Then after a while Unix became commercialized and was not free. So a person by the name of
Richard Stallman created a project called
GNU in 1983 to provide an Unix like operating system for free under
GPL(General Public License). By the year 1990 everything was ready to created a full operating system but there was a problem the GNU
kernel code named
Hurd had failed to attract the interest of developers and was little unstable. And there was several other release from different creators but they also had smiler problems.
This led to a project in
1991 that began in
Hesinki by Linus Torvalds that later became the
Linux kernel. At beginning it was a terminal emulator that was used by Torvalds to access Unix servers. After a while Torvalds noticed that he has written an operating system kernel and on 25
th of August 1991 he announced this to
newsgroup "comp.os.minix" through
Usenet. And later this became the famous Linux that we now today.