“A Linux distribution (also called GNU/Linux distribution by some vendors and users) is a member of the family of Unix-like software distributions built on top of the Linux kernel. Such distributions (often called distros for short) consist of a large collection of software applications such as word processors, spreadsheets, media players and database applications. The operating system will consist of the Linux kernel and, usually, a set of libraries and utilities from the GNU project, with graphics support from the X Window System. Distributions optimized for size may not contain X, and tend to use more compact alternatives to the GNU utilities such as Busybox, uClibc or dietlibc. There are currently over six hundred Linux distributions. Over three hundred of those are in active development, constantly being revised and improved. Linux distributions are software development systems that are constantly revised and improved.”