Ubuntu Releases

Version   Released   Name             End of Support  
 4.10     2004-10-20 Warty Warthog    2006-04-30
 5.04     2005-04-08 Hoary Hedgehog   2006-10-31
 5.10     2005-10-13 Breezy Badger    2007-04-13
 6.06 LTS 2006-06-01 Dapper Drake     2009-06 desktops, 2011-06 servers
 6.10     2006-10-26 Edgy Eft         2008-04-25
 7.04     2007-04-19 Feisty Fawn      2008-10
 7.10     2007-10-18 Gutsy Gibbon     2009-04
 8.04 LTS 2008-04-24 Hardy Heron      2011-04 desktops, 2013-04 servers
 8.10     2008-10-30 Intrepid Ibex    2010-04
 9.04     2009-04-23 Jaunty Jackalope 2011-10 
 9.10     2009-10-29 Karmic Koala     2011-04
10.04 LTS 2010-04-29 Lucid Lynx       2013-04 desktops, 2015-04 servers
10.10     2010-10-10 Maverick Meerkat 2012-04
11.04     2011-04-28 Natty Narwhal    2012-10
11.10     2011-10-13 Oneiric Ocelot   2013-04
12.04 LTS 2012-04-26 Precise Pangolin 2017-04 both desktops and servers
12.10     2012-10-18 Quantal Quetzal  2014-04 both desktops and servers
13.04     2013-04-18 Raring Ringtail  2014-01 both desktops and servers
13.10     2013-10-17 Saucy Salamander 2014-07 both desktops and servers
14.04 LTS 2014-04-17 Trusty Tahr      2019-04
14.10     2014-10-23 Utopic Unicorn   2015-07
15.04     2015-04-23 Vivid Vervet     2016-01
15.10     2015-10-22?Wily Werewolf    2016-07

The above table applies equally to Ubuntu Desktop, Ubuntu Business Desktop Remix, Ubuntu Cloud, Ubuntu GNOME, Ubuntu for Android, Ubuntu Server, Ubuntu Studio, Ubuntu Touch, Ubuntu TV, Edubuntu, Fluxbuntu, Kubuntu, Lubuntu, Medibuntu, Mythbuntu, UbuntuKylin, Xubuntu, Aurora, Baltix, BackBox, BackTrack, BlankOn, BuildX, Bodhi Linux Cubuntu, dyne:bolic, EasyPeasy, ElementOS, elementary OS, Emmabuntus, Galsoft Linux, GendBuntu, Goobuntu, gOS, Guadalinex, Iskolinux, Joli OS, HP Mi, Impi Linux, Karoshii, Kuki Linux, LiMux, Linux Mint, LinuxMCE, LinuxLTE, LliureX, MAX, Molinux, Moon OS, Nova, Netrunner, OpenGEU, Peppermint OS, Pinguy OS, Poseidon Linux, PUD, Qimo 4 Kids, Sabily, Super OS, Trisquel GNU/Linux, TurnKey Linux Virtual Appliance Library, UberStudent, Ubuntu MATE, Vinux, ZevenOS, and no doubt various other variants, some officially sponsored by Canonical, Ltd. and others not. All of those branded variants share a common OS core package set, which in effect is what gets the *buntu version number and branch name.

Early on, Canonical established the convention that each version number would comprise the one-or-two-digit year, a decimal point, then the two-digit month in which release occurred. Thus, because initial release "Warty Warthog" ended up being released in October 2004, it became version 4.10. Because release schedules can slip, a release that's predicted to emerge as "10.02" (on account of an expected February 2010 release window) and referred to by that number in advance of release can end up bearing a "higher" (later-date) number reflecting scheduling slippage.

Baseline paid-support duration is 18 months from release, except for releases designated "LTS" (Long Term Support), often appended as a suffix to qualifying release versions, e.g., "6.06 LTS".

The whimsical names were at first, if memory serves, intended as beta tags, but have become traditional: The form is "adjective animalname", with the short form being just the adjective.