Unix and Unix variants
Unix which is not an acronym was developed by some of the members of the Multics team at the bell labs starting in the late 1960's by many of the same people who help created the C programming language. The Unix today however is the not just the work of a couple of programmers. Many other organizations, institutes, and various other individuals contributed significant additions to the system we now know to day. Complete history and additional information can be found on our Unix history section.
Unix is primarily a command line oriented operating system you can get additional applications such as X-Window which allows you to have a graphic oriented operating system similar to Windows. However, while this is available Unix is still primarily used from the command line.
Because the Unix operating system is an open operating system you will discover that there are various shells. A shell is a large add-on or modification of the Unix operating system, to determine the shell you can type echo $shell at the Unix prompt. When typing this you will receive a response such as /bin/csh which in this case indicates that the Unix you are logged into is a C shell. Another popular shell is the Borne shell which is /bin/sh and Korn shell.
Below is a listing of various Unix variants and brief information about each of them.
* Also see the Linux Variants page.