Note: Ubuntu versions follow a Year.Month scheme and are released every six months. Something like 4.10 would have been released in October of 2004. Six months later in April 2005 comes version 5.04.
4.10 Warty Warthog
Warty was the the release that started it all, and turned this strangely named newcomer distro into something people were talking about. There was little from a technical standpoint that was particularly impressive, but even this first release was uncommonly user-friendly compared to many other Linux distributions at the time.
5.04 Hoary Hedgehog
This was the first release to use X.org instead of XFree86, which is now all but forgotten among modern distributions. A lot of new features came with Hoary, notably power options such as suspend, hibernate and standby support. This was also the first time Ubuntu had a built-in update manager and notifier. Hoary also included some additional Live CD tools like Kickstart, which allows for multiple identical installs, and unified the hardware detection on the Live CD and installed system. This meant that the Live CD could be a much more accurate gauge of how well the installed system would work with your hardware.
5.10 Breezy Badger
With language support greatly increased, Breezy was the most accessible release to date. This release also included improved Bluetooth support, laptop functionality, logical volume management and printer/scanner detection. Usplash was introduced in Breezy, allowing for more graphical startups. Additionally, Breezy came with an improved installer that included a special OEM install so that equipment manufacturers would have a better way to deploy Ubuntu. The ability to dual boot with other operating systems was improved as well, along with better partitioning.
6.06 Dapper Drake
This was the first LTS (Long Term Support) release. Originally planned as 6.04, release was delayed for 2 months so that the final release could be solid enough to warrant the LTS name. Beginning with Dapper, it starts to look more like the Ubuntu we know today. Dapper included an all new graphical installer, network manager, and support for USB installations.
6.10 Edgy Eft
Coming so close behind Dapper, Edgy was a somewhat minor release. The most notable change was probably the switch to Upstart instead of the traditional init system. Upstart was designed to handle not just the order of scripts in system startup, but also events that took place after startup was complete (like plugging in a USB drive). Details on exactly why they wanted to replace init and how they came up with Upstart can be found here.
7.04 Feisty Fawn
Arguably the biggest usability improvement found in Feisty was the assistance Ubuntu provided in acquiring proprietary content (Flash, Java, binary video drivers, etc) once the system was installed. Prior to that, getting Flash or Nvidia drivers working properly could prove to be a major headache, and turned off a lot of prospective users. This also marked the first time Compiz, the 3D desktop effects layer, was included with Ubuntu.
7.10 Gutsy Gibbon
Gutsy, while not a particularly innovative release, still included a fair batch of useful changes. For many, a valuable new feature was the inclusion of NTFS-3G which allowed for full read and write capability to NTFS formatted partitions. Also notable was the support for AppArmor, a application security framework for Linux.
8.04 Hardy Heron
This was Ubuntu’s second Long Term Support release, and came with a large number of improvements. Hardy was the first version to include Wubi, the Windows-based Ubuntu installer, as well as the now standard packages PulseAudio, Brasero, and Totem. Finally, this was the first Ubuntu release to support KVM virtualization.
8.10 Intrepid Ibex
Intrepid was the first to include the popular Live USB Creator, which is one of the many tools that can make remixing Ubuntu surprisingly easy. Another of the more interesting things about Intrepid was the option to easily set up encrypted directories within your home using ecryptfs-utils. This was also the first release to enable a Guest account, stated as being “sufficiently safe to lend your laptop to someone else for a quick email check.”
9.04 Jaunty Jackalope
Ext4, the long awaited filesystem, had its Ubuntu debut in Jaunty, though not yet as default. Bootup speed an other performance tweaks were introduced, and Wacom tablets and multiple monitor setups became much simpler to use. Jaunty also included a newly designed notification system coming out of the desktop panel.
9.10 Karmic Koala
The current stable release, as of this writing, and soon to be replaced by Lucid Lynx. Karmic brought us ext4 as the default filesystem, the first look at the Ubuntu Software Center, and the somewhat controversial GRUB2. Not to be left out of the cloud computing craze, Karmic shipped with Ubuntu One personal cloud service, and the Ubuntu Enterprise Cloud Images.
10.04 Lucid Lynx
We’ll be checking out Lucid in more detail as the release date (April 29, 2010). The development versions can be found here. So far, Lucid plans to completely remove the hardware handler hal, set Nouveau as the default Nvidia driver, add social network integration, and in a that move many will find surprising, change Firefox’s default search to Yahoo!