A remix of Lucid Lynx has been created with only KDE3/Trinity installed, for the convenience of users who are not quite ready to take the jump to KDE4.x.

The main focus of this remix is to keep the mature, stable, and familiar KDE3/Trinity desktop environment available for easy installation and use. Along the way, various bugs have been fixed, and significant enhancements added--see below for more information. Additionally, upstream development is continuing within the KDE3/Trinity fork of KDE, so you will always have access to a mature, up-to-date desktop environment.

This remix follows Kubuntu's release schedule, slightly delayed. Currently the final Lucid Lynx [Kubuntu 10.04] version is available for download from:

New or Improved from Karmic

This section highlights some of the most useful improvements to the KDE3/Trinity system.

Trinity 3.5.12 Backport

An unsupported backport of the latest Trinity 3.5.12 release is available in this PPA:

No further feature updates will be built for Lucid; the packages in that PPA are final barring any needed future security updates.

For a full listing of the new features introduced in Trinity 3.5.12, please visit the official release notes at this page:

KDE3/Trinity 3.5.11
Click image for larger view
Click image for larger view

This release focuses more on backend improvements than user-visible changes. Notably, KDE3 development has been handed off to the Trinity project, and all of the Trinity code is now in a KDE SVN branch, from which packages are built on a regular basis. Many bugs have been fixed and new features have been added; a partial list follows.

System Tray Enhancements

The System Tray icon size is now configurable, per the applicable Free Desktop specification.
NOTE: While most, if not all, Trinity applications now support resizing, many third party applications do not. If you encounter an application that displays incorrect images at system tray sizes other than 22x22 pixels, please report that as a bug to the original application developers, not the Trinity project. Due to the way system tray icons are handled in X11, there is nothing the Trinity project can do to alter this situation.

ICC Support

ICC support has been updated to allow for multiple profiles and automatic application of specified color profiles to individual display outputs. This is perfect for users with laptops and external monitors; simply switch monitors and your color profile is automatically applied!

Task Manager

It is now easier than ever to access the task manager when a program is running amok. Simply right-click on an empty area of the taskbar and select Launch Process Manager!

KDE4.x compatibility

KDE3/Trinity can be installed alongside KDE4.x with no problems. KDE3/Trinity automatically detects and adjusts for KDE4.x programs, so that users can easily run KDE4 applications from within the KDE3/Trinity environment.

Assisting the Project

If you are interested in helping out, please contact:

A Bluetooth developer who could re-activate KDE3/Trinity's Bluetooth functions would be greatly appreciated!

Known Issues

  • None at the moment.

Mailing List

  • There is a mailing list for Kubuntu KDE3/Trinity users available here:
    This is a great place for users to share tips and tricks, and you can also sign up to receive announcements related to KDE3/Trinity under Kubuntu.

Installation of KDE3 in standard Kubuntu/Ubuntu

Long-Term Support

  • I notice that some users are wondering if KDE3/Trinity will be available for Maverick Meerkat [Kubuntu 10.10]. The answer is yes, barring any unforeseen unfixable issues.

  • If you decide to try KDE4, or even move completely away from KDE3, you can do that easily. Simply install the KDE4 kubuntu-desktop package, reboot into your new desktop, and remove the KDE3 packages with your favorite package manager.
    As an aside, KDE4 and KDE3 coexist almost perfectly, so you can even switch back and forth between the two just by selecting the desired environment from the login screen.

Upgrade from 8.04 [Hardy Heron]

  • It is relatively simple to upgrade from Kubuntu 8.04 to Kubuntu 10.04 with KDE3/Trinity, but the process has not been automated.
    You will therefore have to follow these steps to ensure a successful update without losing your KDE settings:

    • 1. Copy your /home/<username>/.kde folder to /home/<username>/.kde3 You will have to do this for all users of the computer that you are upgrading. Make sure that the permissions and ownership of these files are not disturbed in any way. Some KDE settings may still be lost during the transition.

    • 2. Perform the upgrade as you normally would. Eventually, the update utility will inform you that you need to reboot. After doing so, you will have a KDE4 desktop. Don't worry, this is temporary.
    • 3. Using your favorite package manager or a text editor, open your repositories list (/etc/apt/sources.list). Point your browser to, and add the two lines listed at the top of the page under "Karmic".

    • 4. Below those lines, you will see two more lines for Intrepid, and then two commands regarding the GPG signing key. Ignore the Intrepid lines and run those two commands in a terminal. The computer should respond with "OK" after the second command.
    • 5. Using your package manager or the command line, perform a 'fetch updates' (sudo apt-get update).
    • 6. If you don't already have one open, open a new terminal and install the ' kubuntu-desktop-kde3 ' package.
    • 7. After the install has finished, take a look at the end of the output from the apt-get command. If everything went smoothly, with no errors, reboot your computer. You should now be able to select KDE3 as your window manager at the login screen. You can also remove the KDE4 packages with your favorite package manager if you do not want to have KDE4 installed.
  • Once you have upgraded to Intrepid with KDE3/Trinity, Jaunty with KDE3/Trinity, or Karmic with KDE3/Trinity, you will be able to perform future upgrades without having to follow the above steps.

Note: During the install of the kubuntu-desktop-kde3 package, the computer may complain about packages which conflict, causing the apt-get command to (eventually) end with an error. If so, follow up with 'apt-get -f install' to finish the install process.

Installing KDE3/Trinity applications

  • To install the KDE3/Trinity version of a desired application, append a -kde3 suffix onto the package name. For example, to install the KDE3/Trinity version of Amarok instead of the KDE4 version, install the 'amarok-kde3' package instead of the 'amarok' package. This will be persistent across future upgrades. Also, the KDE3/Trinity and KDE4 versions of most applications can be installed at the same time with no problems.

Executing KDE3/Trinity applications from another DE

  • KDE3/Trinity applications now require a special environment to be set up in order to run properly; this prevents conflicts with any portion of KDE4. If you are using these applications from within KDE3/Trinity, then this is automatic and you do not need to do anything to have them run properly. However, if you are attempting to use KDE3/Trinity applications from within KDE4, Gnome, or XFCE/Fluxbox, you will need to set the following environment variables before execution:
    • PATH=/opt/kde3/bin:/opt/kde3/games:/opt/kde3/bin:$PATH
    • KDEDIRS=/usr/:/opt/kde3/
    • KDEHOME=$HOME/.kde3
    • XDG_DATA_DIRS=/opt/kde3/share/:/usr/share/
    • MANPATH=/opt/kde3/share/man
  • KDE3/Trinity applications and libraries now reside in the /opt/kde3 prefix. This means that you must have the kdelibs-data-kde3 package installed, as it creates the correct ldconfig path search file. Without it, none of the KDE3/Trinity applications will be able to find their library files, and will therefore refuse to run.

  • It is very simple to create a shortcut that can properly run KDE3/Trinity applications. Simply type the following into the "command to run" textbox when creating a shortcut in your environment (all one line):
    PATH=/opt/kde3/bin:/opt/kde3/games:/opt/kde3/bin:$PATH KDEDIRS=/usr/:/opt/kde3/ KDEHOME=$HOME/.kde3 XDG_DATA_DIRS=/opt/kde3/share/:/usr/share/ MANPATH=/opt/kde3/share/man <original application command, e.g. k3b or amarok>


We want to hear what you think about the current beta release of Kubuntu 10.04, the Lucid Lynx, with KDE3/Trinity. We want to know if it Rocks, if it is just OK, or if it is flat out wrong. No matter the feedback, as long as it is in line with the Ubuntu Code of Conduct, we would like to hear it.

So what are you waiting for? Head on over to the Feedback Page and let us know!

Kubuntu/Kde3/Lucid (last edited 2010-10-08 01:43:42 by kb9vqf)