Linux
This sites main focus is on Linux.
Linux aludes to the family of Unix-like computer operating systems using the Linux kernel. Linux can be installed on a wide range of computer hardware, ranging from cell phones, tablet computers and video game consoles, to mainframes and supercomputers. Linux is predominantly known for its use in servers; in 2009 it held a server market share ranging between 20--40%. Most desktop computers run either Microsoft Windows or Mac OS X, with Linux having anywhere from a low of an estimated 1--2% of the desktop market to a high of an estimated 4.8% , desktop use of Linux has become increasingly popular recently, partly owing to the popular Ubuntu, Fedora, Mint, and openSUSE distributions and the emergence of netbooks and intelligent phones running an embedded Linux.
The creation of Linux is one of the most prominent examples of free of charge and open source software collaboration; generally all the underlying source code can be used, uninhibitedly modified, and redistributed, both commercially and non-commercially, by anyone under licenses such as the GNU General Public License. Generally Linux is packaged in a format called a Linux distribution for desktop and server use. Linux distributions include the Linux kernel and all of the supporting software required to run a complete system, such as utilities and libraries, the X Window System, the GNOME and KDE desktop environments, and the Apache HTTP Server. Usually used applications with desktop Linux systems include the Mozilla Firefox web-browser, the OpenOffice.org office application suite and the GIMP image editor.
The name "Linux" comes from the Linux kernel, originally written in 1991 by Linus Torvalds. The main supporting user space system tools and libraries from the GNU Project (announced in 1983 by Richard Stallman) are the basis for the Free SoftUnix
The Unix operating system was thought up and implemented in 1969 at AT&T's Bell Laboratories in the United States by Ken Thompson, Dennis Ritchie, Douglas McIlroy, and Joe Ossanna. Unix derived its name as a joke and reference to an experimental operating system that was slow and inefficient called MULTICS. It was first released in 1971 and was initially entirely written in assembly language, a usual practice at the time. Later, in a key pioneering approach in 1973, Unix was re-written in the programming language C by Dennis Ritchie, (with exceptions to the kernel and I/O). The availaptatude of an operating system written in a high-level language allowed easier portaptatude to different computer platforms. With a legal glitch forcing AT&T to license the operating system's source code, Unix rapidly grew and became widely instituted by academic institutions and businesses.
Current development
Torvalds continues to direct the creation of the kernel. Stallman heads the Free Software Foundation, which in turn supports the GNU aspects. Finally, individuals and corporations develop third-party non-GNU aspects. These third-party aspects comprise a vast body of work and may include both kernel modules and user applications and libraries. Linux vendors and communities combine and distribute the kernel, GNU aspects, and non-GNU aspects, with additional package management software in the form of Linux distributions.