Linux is a Unix-like computer operating system family. Linux is one of the most prominent examples of free software and of open source development; its underlying source code is available for anyone to use, modify, and redistribute freely.

The first Linux systems were completed in 1992 by combining system utilities and libraries from the GNU project with the Linux kernel, which led to the coining of the term GNU/Linux. From the late 1990s onward Linux gained the support of corporations such as IBM, Sun Microsystems, Hewlett-Packard, and Novell.

Predominantly known for its use in servers, Linux is used as an operating system for a wider variety of computer hardware than any other operating system, including desktop computers, supercomputers, mainframes, and embedded devices such as cellphones. Linux is packaged for different uses in Linux distributions, which contain the kernel along with a variety of other software packages tailored to its intended use.