Linux distributions (often abbreviated as distros) are made of the Linux kernel and a collection of applications. The operating system will be made up of the Linux kernel and, usually, a set of libraries and utilities from the GNU project, with graphics that come from the X Window System. Small distributions may not contain big window systems full of features like KDE or GNOME, but use small window systems like busybox, uclibc or dietlibc. There are more than three hundred Linux distributions. Most of them are still in development, constantly being improved and changed.
Before the first Linux distributions, a user needed to be an expert on UNIX, knowing what libraries and executables were needed to get the system to boot and run.
Linux distributions started to form after the Linux kernel began to be used by people besides the first Linux programmers.
Early distributions included:
- H J Lu's "Boot-root" a two disk pair with the kernel and the absolute minimal tools to get started.
- MCC Interim Linux, which was made available to the public for download on the FTP server of University of Manchester in February, 1992;
- TAMU, created by individuals at Texas A&M University about the same time, and
- SLS (Softlanding Linux System).
- Yggdrasil Linux/GNU/X, created the first CD-ROM based Linux distribution.
SLS was not well-maintained, so Patrick Volkerding created a distribution based on SLS, which he called Slackware; released July 16, 1993. This is the oldest being developed.
People who used computers wanted to use Linux distributions as replacements to Microsoft Windows operating systems on the PC, Mac OS on the Apple Macintosh and proprietary versions of Unix.
Distributions are normally split into packages. Each package has a certain application or service. Examples of packages include a collection of fonts, or a web browser.
The package is usually given as compiled code, with installation and removal of packages done by a package management system. Linux distributions usually contain much more software than Microsoft Windows or Mac OS X.
Well-known Linux distributions include:
Tools for choosing a Linux distributionEdit
There are tools available to help people make the decision easier. 
Screenshots of common distributionsEdit
A few screenshots of common distributions just after installation:
- ↑ The Slackware Linux Project: Slackware Release Announcement
- ↑ "zegenie Studios Linux Distribution Chooser". Archived from the original on 2009-05-23. Retrieved 2008-07-14.
- ↑ "(:^tuxs.org) Linux Distribution Chooser". Archived from the original on 2008-08-20. Retrieved 2008-07-14.
- ↑ "Desktop Linux At Home - Distro Selector". Archived from the original on 2011-07-22. Retrieved 2008-07-14.
- Distribution Reviews
- Hardware support by Linux distribution Archived 2009-05-13 at the Wayback Machine
- Linux Distribution Chooser Archived 2009-05-23 at the Wayback Machine by Zegenie Studios
- The Linux Mirror Project Download Linux Distributions over BitTorrent