Unix is the first Operating system in the world, developed by Kem Thompson and Dennis Ritchie in 1969 at Bell Lab by AT&T Company
IBM : AIX
SGI : IRIX
HP : HP
Sun : Solaris
FSF :–> Free software foundation organization, they start a project by name GNU. The mail aim of this project is to develop such a O.S that can run on any platform.
In 1991, a student Linus Tarvalds developed a kernel named Linus’s Kernel plus GNU application called Linux O.S
Linux is a open source technology.
Different companies that provide Linux in Market are Redhat, SuSe, Mandrake, Turbo, Knoppix etc.