Multics system (Multiplexed Information and computing service) was been creating by AT&T (telephonic American company) at Bell Labs from 1964 until A&T left the project because it is too hard to manage and maintain.
Multics used revolutionary and sophisticated technology and solution, many of this are still used today but it was so complex.
From Multix, Ken Thompson and Dennis Ritchie, two researcher at Bell Labs, developed “Unics” (Uni-plexed Information and computer services) that will become “Unix” after soon.
the first version of Unix was totally written in Assembly, the second version in B (a very low level language, precursor of C) and the definitive version in C (C is B but with more data type, C was thought and created by Ritchie) C is also used in the recent version of Unix.
C, allowed Unix to be multi-platform and this make Unix famous allover the world.
In 80s were born a lot of different version of Unix, all of this are thought for industries and University, there aren’t for personal uses. Stallman developed GNU.
what is GNU? GNU is NOT UNIX, and what is GNU? GNU is NOT UNIX (it is a recursive acronym)
this system was based and inspired to Unix but it not contain any row of Unix.
Stallman also invented GPL (Gnu general Public License) a public license for open source code.
In 90s Linus Torvalds developed the Linux kernel used in Unix systems.