See also: Operating Systems | POSIX | *Nix

UNIX is a cross-platform operating system written in C. It has become the mainstay for servers both large and small.

Although capitalized, UNIX is not an acronym, a play on the term MULTICS or a multi-user operating system. It is also a registered trademark of The Open Group – www.unix.org. Its derivatives such as Linux and BSD all share a common ancestry intermingled with UNIX. Any current or past UNIX is frequently referred to as *NIX.

  • m2p2 – netmeister.org’s missing man pages project


UNIX design principles

  1. Small is beautiful.
  2. A program should do one thing well.


  • Allows for UNIX scripting and development that doesn’t re-invent the wheel
  • More secure (and often faster) by using time-tested programs
  • Entire UNIX operating systems can run on a single 1.4 meg floppy disk (sometimes smaller)
  • Many applications are open-source and benefit from community development and testing

For instance, a basic program could be written to run daily using chron and send files using FTP to a server with a secure tunnel system using stunnel. All three programs are already created and well-tested, allowing the programmer to focus on the why instead of the how and existing features can be added to the program/script without difficulty.


  • Often alien and inaccessible to individuals new to UNIX
  • A learning curve is associated with learning all these smaller programs

Many UNIX systems simplify their user-interfaces with programs such as GNOME and KDE. These window managers act as a front-end for many command-line operations and are fast approaching Windows and Macintosh in terms of usability. Mac OS X runs Aqua, a proprietary window manager atop a specialized UNIX-like system called “Darwin.”

This system also allows for tiny UNIX distributions that can be placed on a floppy or installed on older hardware.

Operating Systems with their foundation in the Unix world


Run UNIX on other systems:

Related Topics, Unix terms

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