By Terry Relph-Knight, ZDNet UK, 26 April, 2012 12:10
Ubuntu 12.04 LTS, codenamed Precise Pangolin and released today, is a Long Term Support (LTS) version, scheduled to be supported for five years. The emphasis for an LTS release is normally on consolidation and stability, but there are several new features — notably the HUD (Head-Up Display). As with most Ubuntu releases, Precise Pangolin takes the opportunity to rev the Linux kernel version; the Unity interface also advances to version 5.10 and there are a number of cosmetic tweaks plus a new sound theme.
Ubuntu founder Mark Shuttleworth's plan is to migrate Ubuntu from the 2D X Window System toWayland, a 3D OpenGL-based display management system, with X applications supported via a compatibility mode. There was a rumour that a technical preview of Wayland might be released with Ubuntu version 12.04. While this does not seem to be the case, there is an Ubuntu Wiki for Wayland that explains future plans and lists a PPA for early testers.
Ubuntu 12.04 images can be downloaded from the Ubuntu web site. Starting with Precise Pangolin, the site promotes the 64-bit image over the 32-bit one. Contrary to some early rumours, the ISO images will still fit on a single CD.
The Linux 3.2 kernel
Precise Pangolin graduates from version 3.0 of the Linux kernel used in Ubuntu 11.10 (Oneiric Ocelot) to version 3.2. This sees a larger-than-usual number of improvements because it incorporates queued-up changes that failed to make it into the delayed previous release.
There are improvements in the Ext4 file system that should boost performance with large files, and changes for CIFS or Samba sharing that should significantly improve throughput for such shares. There are also numerous new and improved drivers for graphics and Wi-Fi hardware, which should please notebook users, plus improvements in memory management that should improve response to user input during high load times. According to Linus Torvalds, these changes in kernel 3.2 should be quite apparent to end users.
RC6, the Intel power-saving technology, is enabled by default for Sandy Bridge systems in the Ubuntu 12.04 kernel, and should help to deliver improved notebook battery life. Disabled in beta 1, AUFS (Another UnionFS, a stackable unification file system) has been re-enabled due to concerns over its possible replacement OverlayFS. Ubuntu's developers still plan to replace AUFS when a suitable solution emerges.
It may seem hard to believe, but Ubuntu's controversial Unity shell is already at version 5.10. The login screen has a new look with new buttons and animation (even though a shell other than Unity can be chosen at login, Ubuntu's developers call this the Unity Greeter):
The new-look Unity Greeter shell menu: here, the GNOME desktop has been added as a post-OS install choice
Unity 2D has been updated, and differences in appearance between it and Unity 3D are now quite subtle: for example, Launcher bar items only appear to stack in Unity 3D.
As anticipated, this release of Unity includes the Head-Up Display or HUD, a predictive command feature that's toggled on and off by tapping the left-hand Alt key. Commands can be selected by moving the highlight with the arrow keys and executed by pressing the Return key, or directly executed by mouse-clicking a choice. Sometimes the suggestions made by HUD can seem a little wild.
The new Head-Up Display (HUD) offers a list of suggestions based on user input
The stability and ease-of use of Unity's multi-monitor mode has been improved, and has been demonstrated running a system with six monitors. The System Settings / Displays panel now has a selection to display the Launcher bar either on all displays in a multi-monitor setup, or only on the primary display; there's also an on/off toggle for sticky edges.
This screenshot is for the Displays panel on a system with only one display, but the new Launcher and sticky edges options can still be seen
Reveal signalling for the Launcher has been added. Now when the Launcher is concealed and the mouse cursor is pushed against the left edge of the display, a shadowed border appears, signalling that the Launcher is about to be revealed. The reveal behaviour for the Launcher (and some other settings) can be changed in the Appearance panel to reveal only if the top left corner is nudged.
The appearance of Launcher tooltips and quicklists has been improved and the Dash, Workspace and Bin icons now borrow the average colour of the desktop wallpaper (also referred to as 'chameleonic behaviour'). Mouse-over states in Dash are now signalled with a more visible highlight, for example in the lens bar.
The quicklist for the Home folder
For those who find the Launcher icons too large, there is now an icon size slider in the Appearance settings panel (the two extremes of icon size are shown in the composite image of the Launcher above): unfortunately this feature is not available in Ubuntu 2D
A new lens, the Video lens, has been added to Dash that brings together access to both online video — such as the BBC iPlayer and YouTube — and access to offline clips stored in the Video folder.
The new Video lens in Dash
The File lens, previously limited to Zeitgeist searches, is now global in scope and can find files not previously accessed.
LIMs (Locally Integrated Menus), an optional Unity feature that adds a title bar and drop-down text menus to unmaximised application windows, were not ready for this release and are expected to appear later this year — possibly as an update, or in Ubuntu 12.10. At present some applications, LibreOffice for example, retain their menus within their own window, while in others — including Brasero — the menu moves to the Ubuntu menu bar at the top of the display.