Linux (operating system)

Linux is a Unix-like computer operating system family that uses the Linux kernel. A Linux system which includes system utilities and libraries from the GNU Project is sometimes referred to as GNU/Linux.

Linux is commonly packaged in distributions (also known as "distros"), such as Debian or Red Hat Enterprise Server. A distribution consists of the Linux kernel and software bundled by the provider and is generally maintained by the distributor. Most distributions are free of cost, while some cost money.

Initially developed and used primarily by individual enthusiasts on personal computers, Linux has since gained the support of corporations such as IBM, Sun Microsystems, Hewlett-Packard, and Novell, Inc., and has risen to prominence as an operating system for servers; Netcraft reported in September 2006 that seven of the ten most reliable internet hosting companies run Linux on their web servers[1].

Linux is used in devices ranging from supercomputers to mobile phones, and has a foothold in the personal computer and business desktop markets.

The current version of the Linux kernel is 2.6.20 as of February 2007. The first number refers to the kernel version. The Linux kernel has been on version 2 since 1996. The second number is called the major version number. It has been major version 6 since December 2003. The third number is the minor revision, and reflects the addition of drivers or features to the kernel. It is changed much more frequently than the first two numbers. It has been 20 since February 4th. A fourth digit is sometimes used in the event of bug fixes or security updates of a critical nature.