What is Linux?

Linux is a generic term commonly used to refer to Unix-like computer operating systems which use the Linux kernel. Linux is one of the most prominent examples of free software and open source development; typically all the underlying source code can be freely modified, used, and redistributed by anyone.

The name "Linux" comes from the Linux kernel, originally written in 1991 by Linus Torvalds. The system's utilities and libraries usually come from the GNU operating system, announced in 1983 by Richard Stallman. The GNU contribution is the basis for the alternative name GNU/Linux.

Linux's functionality, adaptability and robustness, has made it the main alternative for proprietary Unix and Microsoft operating systems. IBM, Hewlett-Packard and other giants of the computing world have embraced Linux and support its ongoing development. Well into its second decade of existence, Linux has been adopted worldwide primarily as a server platform. Its use as a home and office desktop operating system is also on the rise. The operating system can also be incorporated directly into microchips in a process called "embedding" and is increasingly being used this way in appliances and devices.

Design

Linux is a modular Unix-like operating system. It derives much of its basic design from principles established in Unix during the 1970s and 1980s. Linux uses a monolithic kernel, the Linux kernel, which handles process control, networking, and peripheral and file system access. Device drivers are integrated directly with the kernel.

Much of Linux's higher-level functionality is provided by separate projects which interface with the kernel. The GNU userland is an important part of most Linux systems, providing the shell and Unix tools which carry out many basic operating system tasks. On top these tools form a Linux system with a graphical user interface that can be used, usually running in the X Window System.