Ubuntu is a computer operating system. It is often rated as the most popular of the many Linux distributions. Ubuntu's goals include providing an up-to-date yet stable Linux distribution for the average user and having a strong focus on usability and ease of installation. Ubuntu is a derivative of Debian, another free operating system. Ubuntu is sponsored by Canonical Ltd, which is owned by South African entrepreneur Mark Shuttleworth. The word ubuntu is Zulu for "humanity". This Linux distribution is named as such to bring the spirit of the philosophy to the software world. Ubuntu is free software and can be shared by any number of users.

 Kubuntu and Xubuntu are official subprojects of the Ubuntu project, aiming to bring the KDE and Xfce desktop environments, respectively, to the Ubuntu core (by default Ubuntu uses GNOME for its desktop environment). Edubuntu is an official subproject designed for school environments and should be equally suitable for children to use at home. Gobuntu is an official subproject that is aimed at adhering strictly to the Free Software Foundation's Four Freedoms. Ubuntu JeOS (pronounced "Juice") is the newest official subproject. JeOS is a concept for what an operating system should look like in the context of a virtual appliance.

 Ubuntu releases new versions every six months, and supports those releases for 18 months with daily security fixes and patches to critical bugs. LTS (Long Term Support) releases, which occur every two years, are supported for three years for desktops and five years for servers. The most recent version, Ubuntu 8.04 LTS (Hardy Heron), was released on April 24, 2008, although an update, Ubuntu 8.04.1 LTS, was released on July 3, 2008. The next version will be 8.10 (Intrepid Ibex) and is scheduled for release in October 2008.

 History and development process

 Ubuntu's first release was on October 20, 2004, as a temporary fork of the Debian project. This was done so that a new version of Ubuntu could be released every six months, resulting in a more frequently updated system. Ubuntu releases always include the most recent GNOME release, and are scheduled to be released about a month after GNOME. In contrast with previous general-purpose forks of Debian—such as MEPIS, Xandros, Linspire, Progeny and Libranet, many of which relied on proprietary and closed source add-ons as part of their business model—Ubuntu has stayed closer to Debian's philosophy and uses free (libre) software most of the time.

 The Ubuntu logo and typography has remained the same since that first release. The hand-drawn, lowercase OpenType font used is called Ubuntu-Title and was created by Andy Fitzsimon. The font is distributed under the terms of the GNU Lesser General Public License (LGPL) and use with logos derived from the Ubuntu logo is encouraged. The font is available as a package for Ubuntu.

 Ubuntu packages have generally been based on packages from Debian's unstable branch: both distributions use Debian's deb package format and APT/Synaptic to manage installed packages, although Debian and Ubuntu packages are not necessarily binary compatible with each other.[19] Ubuntu cooperates with Debian—to some extent pushing changes back to Debian, although there has been criticism concerning lack of occurrence.[20] Many Ubuntu developers are also maintainers of key packages within Debian. However, Ian Murdock, the founder of Debian, criticized Ubuntu packages for incompatibilities with Debian, saying Ubuntu had diverged too far from Debian Sarge to remain compatible.

 Ubuntu is currently funded by Canonical Ltd. On July 8, 2005, Mark Shuttleworth and Canonical Ltd announced the creation of the Ubuntu Foundation and provided an initial funding of US$10 million. The purpose of the foundation is to ensure the support and development for all future versions of Ubuntu. Mark Shuttleworth describes the foundation as an emergency fund in case Canonical's involvement ends.

 Ubuntu 8.04, released on April 24, 2008, is the current Long Term Support (LTS) release. Canonical has released previous LTS versions separated by two years, and has committed to releasing the next LTS version in 2010, two years after 8.04.

 Vendor support

 A number of vendors offer computers with Ubuntu pre-installed. Dell and Tesco have provided this option since 2007, while System 76 has done so since November 2005. Dell and System76 customers are able to choose between 30-day, three-month, and yearly Ubuntu support plans through Canonical, Ubuntu's parent company. Dell has increased the availability of Ubuntu-driven computers by offering them for sale in the United Kingdom, France, Germany, Canada, Spain, and Latin America. Selected Dell machines running Ubuntu 7.10 and 8.04 have proprietary, legal DVD playback capabilities using LinDVD. Dell computers running Ubuntu 8.04 include extra support for ATI Video Graphics, Dell Wireless, Fingerprint Readers, HDMI, Bluetooth and MP3/WMA/WMV.

 Features

 Ubuntu focuses on usability, including the widespread use of the sudo tool for administrative tasks. The Ubiquity installer allows installing Ubuntu 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. The default appearance of the user interface in the current version is called Human and is characterized by shades of brown and orange.

 The most recent version of Ubuntu comes installed with a wide range of software including: the OpenOffice.org productivity suite, the internet browser Firefox, the instant messenger Pidgin (formerly known as Gaim), the BitTorrent client Transmission and the raster graphics editor GIMP. Several lightweight card, puzzle games, and board games are pre-installed including Sudoku and chess. Ubuntu has all networking ports closed by default for added security, although its firewall, which offers more fine-grained control of incoming and outgoing connections, is installed but not enabled. Ubuntu is available in many languages. GNOME 2.22—the default desktop environment of Ubuntu 8.04—offers support for 46 languages. There are numerous ways to install Ubuntu.

 Live CD

 Installing Ubuntu is generally done with the Live CD, which allows a user to try out the operating system before permanently installing it. Ubuntu can also be used without a hard-disk as it can be run directly from a flash drive. This is particularly useful in testing for hardware compatibility and driver support. The CD also contains the Ubiquity installer, which guides the user through the permanent installation process. Live CDs are mailed freely to anyone upon request, and CD images of all current and past distributions are available for download. Installing from the CD requires a minimum of 64 MB RAM.

 Support for migration from Microsoft Windows was introduced in April 2007, when Ubuntu 7.04 was released. The new migration tool, called Migration Assistant, imports Windows users' bookmarks, desktop background (wallpaper), and various settings for immediate use in the Ubuntu installation.

 Wubi allows the distribution to be installed on a virtual loop device requiring no partitioning. Wubi also makes use of the Windows migration tool to import users' settings. Wubi was initially developed as an independent project, and as such versions 7.04 and 7.10 were released as unofficial distributions. Wubi was later merged with Ubuntu, and as of 8.04-alpha5, Wubi can also be found in the Ubuntu Live CD. Another program, UNetbootin, makes it possible to install Ubuntu on a USB drive or Windows partition using an ISO file.

 Many programs exist to create a customized Live CD/DVD from an existing Ubuntu installation, such as remastersys, the Ubuntu Customization Kit and Reconstructor.

 Alternate installation

 In addition to the Live CD, Ubuntu can be installed through alternate methods. One such method is the alternate install CD.

 The alternate install CD is an alternative installation disk designed for specialist installations of Ubuntu by providing a text-based rather than graphical installation. The alternate install CD allows for the creation of pre-configured OEM systems, for the upgrading of older installations without network access, and for installation on systems with less than 320 MB of RAM. The alternate install CD also allows LVM and/or RAID partitioning to be set up, as well as the encryption of partitions using dm-crypt. The alternate install CD is not a Live CD.

Default login screen for Ubuntu 8.04 (Hardy Heron)'s server edition

Default login screen for Ubuntu 8.04 (Hardy Heron)'s server edition

 Ubuntu can also be installed over a network via the network install CD. The network install CD installs Ubuntu directly from an Ubuntu mirror. Installation from a mirror ensures that installed packages are up-to-date. The network install CD contains only the kernel, to start up the installation. The installation is text-based.

 The final alternate installation method is used to install Ubuntu Server. The server install CD contains all packages needed for installation without a network connection. The server installation of Ubuntu does not install a graphical user interface.

 Releases

 Each release has both a code name and a version number. The version number is based on the year and month of release. For example, the very first release of Ubuntu 4.10 was released on October 20, 2004. Consequently, version numbers for future versions are provisional; if the release is delayed until a different month to that planned, the version number changes accordingly. The first characters of release names form an alphabetical series. This makes it easier to determine which release is newer when comparing two. Exceptions are the first few releases that should have begun with A, B, C.

 Releases are timed to be approximately one month after GNOME releases, which are in turn about one month after releases of X.org. Consequently, every Ubuntu release comes with a newer version of both GNOME and X. Release 6.06—and recently 8.04—have been labeled as a Long Term Support (LTS), to indicate support with updates for three years on the desktop and five years on the server, with paid technical support available from Canonical Ltd