Unix was developed in 1969 at Bell Labs by Ken Thompson and Denis Ritchie and released in 1971, written in Assembly Language. Linux was created in 1991 by Linus Torvalds as a free and open source operating system based on the Unix kernel and initially developed for Intel x86 computers. There are several popular Linux distributions like Ubuntu, CentOS, and Fedora that are free and open source, while Red Hat Enterprise Linux and SUSE Enterprise are commercial versions. Linux is commonly used in servers, supercomputers, routers, and embedded systems.