UNIX

UNIX

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Native name
Developer	AT&T Bell Labs
Written in
OS family
Working state
Source model	Initially closed source, later versions were open source
Initial release
Released to manufacturing
General availability
Latest release

UNIX is a family of multitasking, multiuser operating systems that derive from the original AT&T UNIX, development of which began in the late 1960s at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others. Both a software and cultural icon, UNIX has significantly influenced all modern operating systems, most notably via its Unix philosophy of small, modular tools that each perform a limited, well-defined function.

History

The development of UNIX began in 1969 at a time when the concept of a portable, multi-tasking and multi-user system was a paradigm shift. The original UNIX was developed by Ken Thompson and Dennis Ritchie. UNIX was designed to be a small, flexible system used exclusively by programmers.

Due to its portability, flexibility, and power, UNIX quickly spread to academic institutions and businesses. In the 1980s, AT&T licensed UNIX to third-party vendors, leading to various commercial and non-commercial variants, including BSD, Solaris, and System V. The introduction of these variants led to significant fragmentation within the UNIX community, which the POSIX standard later partly addressed.

Features

UNIX systems are characterized by a hierarchical file system, TCP/IP networking, multi-tasking, and multi-user capabilities. Features include:

• Command-line interface: Most UNIX systems are equipped with a command-line interface (CLI), although graphical user interfaces (GUIs) like GNOME and KDE are also widely available.
• Shell scripting: The UNIX shell is both a command interpreter and a programming language, allowing complex programs to be written with simple commands.
• Pipes and filters: UNIX makes heavy use of "pipes", which allow the output of one program to serve as the input to another program.

Impact

UNIX has been influential in the development of many other operating systems. Its design philosophy has a profound impact on the design of Linux, which mimics its architecture, and Apple's macOS, which is based on BSD. The UNIX environment and the client-server program model were essential elements in the development of the Internet.

UNIX has also directly or indirectly influenced many important software tools and scripting languages, such as C, Perl, Python, and others.

Licensing

Originally, UNIX was proprietary software, but through various projects and changes in ownership, many of its derivatives became open source. For example, FreeBSD and OpenBSD are open source derivatives of BSD, which was originally based on UNIX.

See also

• List of Unix commands
• Unix-like
• Comparison of operating systems