Draft:Operating system/Operating Systems/Linux

Portal:Engineering_and_Technology/School:Computer_Science/Topic: Operating Systems/GNU-Linux

Welcome to the Department of Linux

Linux is commonly used to refer to a GNU/Linux operating system. Modern operating systems including both Linux and Windows consist of two main parts. These are the kernel, which talks directly to system hardware, and 'user land' which is where any program users interact with are run. As vital as the kernel is it is still only about 4% of an operating system. The other 96% is provided by the 'user land' tools. In the case of a normal GNU/Linux system Linux refers only to the kernel. The user land tools are mostly provided by the GNU project.

The Linux kernel is a clone of the commercial operating system UNIX. It was created from scratch by Linus Torvalds and is now maintained by a volunteer group of coders distributed around the globe. Linux is now developed under the GNU General Public License (GPL).

The GNU Public Licence is also used on all software produced by the GNU project. This is the vast majority of a full GNU/Linux system. This licence states that software can be downloaded, used, and changed by anyone without charge on the condition that anyone distributing a changed version also has to provide the source code to their changes. GNU is a recursive acronym for 'GNU is Not Unix.'

Many Linux system administrators believe the 'open source' model used by GNU/Linux results in more reliable and secure code.

Distributions
The Linux operating system is open source. (http://www.linux-diff.net/) There are thousands of application programs running on it. A particular selection of operating system components and applications are called a 'distribution'. Everybody is entitled to compose a distribution. However most users tend to stick to more well know distributions.

Distributions are full packaged operating systems. You can download them, install them, and use them to run your programs! Here is an ( incomplete ) list of the major players in the Linux distro world:
 * Trisquel - GNU/Linux is a fully free operating system for home users, small enterprises and educational centers.


 * Red Hat - The biggest distributor of Enterprise Linux, with its flagship Red Hat Enterprise Linux (RHEL) products. It is free as in Freedom but offered with support contract based on user requirements. Market focus on the Enterprise market space.
 * Fedora - Formerly known as Fedora Core, It is a free open source Red Hat sponsored distribution. Fedora is the upstream of Red Hat Enterprise Linux which means all new features will come out first in Fedora before possible inclusion into Red Hat Enterprise Linux ( RHEL ) upon maturity and enough demand to create support services around it.
 * CentOS - A binary compatible Linux distribution with Red Hat Enterprise Linux built using the freely available source code of Red Hat Enterprise Linux minus the support contract and Red Hat trademark.
 * Debian - The largest community-run Linux distribution on earth with its own Debian Social Contract and Constitution. Large package database, excellent hardware detection. Lots of distribution built their Linux based on Debian including Ubuntu.
 * Ubuntu - One of the latest and widely used. Immensely popular for its easy install process and ease of use. Ubuntu includes  some non-free (as in freedom), but convenient software. Based on Debian.
 * Linux_Mint - User friendly setup for those used to Windows OS. Easily usable right out of the box. Currently the 4th most popular OS used. Free and open source.
 * Knoppix - The best for hardware detection, which makes the whole thing boot slower, still, if you can't get Knoppix installed, then you really must be trying to make things difficult.
 * SUSE - The second largest Linux distribution company in the world. Being bought over by Novell and famous for its Suse Linux Enterprise Server (SLES) and SUSE Linux Enterprise Desktop (SLED). Free as in freedom with supports contract around it.
 * openSUSE - Novell sponsored free open source distro, openSUSE is to SUSE Linux what Fedora is to Red Hat Enterprise Linux.
 * Oracle Linux
 * Gentoo - Designed for enthusiasts, professionals, and people who want to squeeze every last ounce of performance out of their machine. Most of the software is provided as source, instead of in a binary form.
 * Slackware - The oldest distro that is still maintained.
 * Puppy_Linux - Runs completly in RAM and is therefore very fast.
 * Damn Small Linux - A Linux distro at only 50mb!
 * Tiny Core Linux - A Linux distro at only 10mb!!
 * rPath- An appliance friendly distro that uses conray for package management. This allows users to have a server running on their desktop or laptop machine completely independently.  Many preconfigured server configurations are available for many of the virtural machines, such as VMplayer.

See also Linux distribution and the List of Linux distributions at Wikipedia

Learning projects

 * Linux Documentation Project
 * Linux Server Administration

Open source software

 * Conary - A distributed package system


 * Linux Documentation Project

pages at or linked from kernel.org

 * Linux Kernel Hackers' Guide (from the Linux Documentation Project)
 * Tour of the kernel