Ubuntu is a computer operating system based on the Debian GNU/Linux distribution and is distributed as free and open source software.

Ubuntu is a computer operating system based on the Debian GNU/Linux distribution and is distributed as free and open source software with additional proprietary software available.

It is named after the Southern African ethical ideology Ubuntu ("humanity towards others").Ubuntu provides an up-to-date, stable operating system for the average user, with a strong focus on usability and ease of installation.

Web statistics suggest that Ubuntu's share of Linux desktop usage is about 50%,and upward trending usage as a web server.

Ubuntu is composed of many software packages, of which the vast majority are distributed under a free software license (also known as open source). The main license used is the GNU General Public License (GNU GPL) which, along with the GNU Lesser General Public License (GNU LGPL), explicitly declares that users are free to run, copy, distribute, study, change, develop and improve the software.

Ubuntu is sponsored by the UK-based company Canonical Ltd., owned by South African entrepreneur Mark Shuttleworth. By keeping Ubuntu free and open source, Canonical is able to utilize the talents of community developers in Ubuntu's constituent components. Instead of selling Ubuntu for profit, Canonical creates revenue by selling technical support and from creating several services tied to Ubuntu.

Canonical endorses and provides support for three additional Ubuntu-derived operating systems: Kubuntu, Edubuntu and Ubuntu Server Edition. There are several other derivative operating systems including local language and hardware-specific versions.

Canonical releases new versions of Ubuntu every six months and supports Ubuntu for eighteen months by providing security fixes, patches to critical bugs and minor updates to programs. LTS (Long Term Support) versions, which are released every two years, are supported for three years on the desktop and five years for servers. The latest version of Ubuntu, 10.04 (Lucid Lynx), is such an LTS version, and was released on April 29, 2010.

Kate Stewart has announced the availability of the second alpha release of Ubuntu 11.10, code name "Oneiric Ocelot": "Welcome to Oneiric Ocelot alpha 2, which will in time become Ubuntu 11.10. Alpha 2 is the second in a series of milestone images that will be released throughout the Oneiric development cycle. New packages showing up for the first time include: Linux Kernel 3.0-rc5, GCC 4.6.1 compiler, Firefox 5.0, Thunderbird 5.0, a Mesa 7.11 snapshot. Alpha 2 ships GNOME 3.0, with some parts already upgraded to the 3.1.2 alpha releases. Unity, the theme, and Ayatana scrollbars were updated for GTK+/GNOME 3.

See the release announcement and release notes for full details about this alpha build.

Download (SHA256): oneiric-desktop-i386.iso (714MB, torrent), oneiric-desktop-amd64.iso (715MB, torrent). Xubuntu 11.10 alpha 2 (download) and Edubuntu 11.10 alpha 2 (download) can be obtained from usual locations, but Kubuntu 11.10 alpha 2 images will not be available

Recent releases:

• 2011-07-07: Development Release: Ubuntu 11.10 Alpha 2
• 2011-06-02: Development Release: Ubuntu 11.10 Alpha 1
• 2011-04-28: Distribution Release: Ubuntu 11.04
• 2011-04-14: Development Release: Ubuntu 11.04 Beta 2
• 2011-03-31: Development Release: Ubuntu 11.04 Beta 1
• 2011-03-04: Development Release: Ubuntu 11.04 Alpha 3

Ubuntu focuses on usability. The Ubiquity installer allows Ubuntu to be installed to the hard disk from within the Live CD environment, without the need for restarting the computer prior to installation. Ubuntu also emphasizes accessibility and internationalization to reach as many people as possible.

Beginning with 5.04, UTF-8 became the default character encoding, which allows for support of a variety of non-Roman scripts. As a security feature, the sudo tool is used to assign temporary privileges for performing administrative tasks, allowing the root account to remain locked, and preventing inexperienced users from inadvertently making catastrophic system changes or opening security holes. PolicyKit is also being widely implemented into the desktop to further harden the system through the principle of least privilege.

Ubuntu comes installed with a wide range of software that includes OpenOffice.org, Firefox, Empathy (Pidgin in versions before 9.10), Transmission, GIMP (in versions prior to 10.04), and several lightweight games (such as Sudoku and chess). Additional software that is not installed by default can be downloaded using the package manager. Ubuntu allows networking ports to be closed using its firewall, with customized port selection available. End-users can install Gufw and keep it enabled.GNOME (the current default desktop) offers support for more than 46 languages.

Ubuntu can also run many programs designed for Microsoft Windows (such as Microsoft Office), through Wine or using a Virtual Machine (such as VMware Workstation or VirtualBox).

Releases.

Version	Code name	Release date
4.10	Warty Warthog	2004-10-20
5.04	Hoary Hedgehog	2005-04-08
5.10	Breezy Badger	2005-10-13
6.06 LTS	Dapper Drake	2006-06-01
6.10	Edgy Eft	2006-10-26
7.04	Feisty Fawn	2007-04-19
7.10	Gutsy Gibbon	2007-10-18
8.04 LTS	Hardy Heron	2008-04-24
8.10	Intrepid Ibex	2008-10-30
9.04	Jaunty Jackalope	2009-04-23
9.10	Karmic Koala	2009-10-29
10.04 LTS	Lucid Lynx	2010-04-29
10.10	Maverick Meerkat	2010-10-10

There are two Ubuntu releases per year, using the year and month of the release as the version number. The first Ubuntu release, for example, was Ubuntu 4.10 and was released on October 20, 2004. Version numbers for future versions are provisional; if the release is delayed the version number changes accordingly.

Ubuntu releases are also given alliterative code names, using an adjective and an animal (e.g., "Dapper Drake" and "Intrepid Ibex"). With the exception of the first three releases, code names are in alphabetical order, allowing a quick determination of which release is newer. Commonly, Ubuntu releases are referred to using only the adjective portion of the code name.

Releases are timed to be approximately one month after GNOME releases (which in turn are about one month after releases of X.org). Consequently, every Ubuntu release comes with an updated version of both GNOME and X. Selected releases (such as 6.06 Dapper Drake and 8.04 Hardy Heron) have been labeled as Long Term Support (LTS) versions, indicating that they are supported (with updates) for three years on the desktop and five years on the server, as compared to the 18-month support period for non-LTS releases.

The current release is 10.04 LTS Lucid Lynx, released on April 29, 2010.
The next release will be 10.10 Maverick Meerkat, to be released on October 10, 2010. This is a departure from the traditional schedule releasing at the end of October.

Variants.

Several official and unofficial Ubuntu variants exist. These Ubuntu variants install a set of packages that differ from the original Ubuntu distribution.

Official variants store packages and updates in the same repositories as Ubuntu, so that the same software is available for each of them and is generally compatible between the official variants. The Ubuntu derivatives that are fully supported by Canonical are:

* Kubuntu, a desktop distribution using KDE rather than GNOME.
* Edubuntu, a GNOME-based subproject and add-on for Ubuntu, designed for school environments and home users.
* Ubuntu Server Edition.
* Ubuntu JeOS, "Just enough Operating Systems" for virtual appliances.
* Ubuntu Studio, a distribution made for professional video and audio editing, comes with higher-end free editing software and is a DVD .iso image unlike the live CD the other Ubuntu distributions use.

The following are Canonical-sponsored derivatives:

* Xubuntu, a "lightweight" distribution based on the Xfce desktop environment instead of GNOME, designed to run more efficiently on low-specification computers.
* Lubuntu, which uses the LXDE desktop environment, targeted at "normal computers" with 128Mb of RAM as the bottom line configuration
* Ubuntu MID Edition, an Ubuntu edition that targets Mobile Internet Devices.
* Ubuntu Netbook Edition, (formerly Ubuntu Netbook Remix) designed for netbooks and other ultra-portables.

There are also many unofficial variants, unsponsored derivatives, and other localizations and customizations not controlled or guided by Canonical Ltd., which generally contain customizations that have been created for specific goals. For example, Mythbuntu is based on Ubuntu and MythTV and provides open-source applications for recording TV and acting as a media center.