Setting the default display manager in Ubuntu/Kubuntu

One of the good things of Ubuntu, and Linux in general, is that there is a wide range of windows managers. You aren't stuck to the look and feel given by a company, but you can choose among several options. Two of the most popular windows managers in the Linux world are GNOME and KDE. The default manager in Ubuntu is GNOME, but if you use Kubuntu, the default is KDE.

Kubuntu and Ubuntu are very much the same thing but the looks are different, using different user interface philosophies. Ubuntu/GNOME is robust and ideal for those who want to use the computer for productivity, whereas Kubuntu/KDE is flexible and customisable and ideal for those who like looking "under the hood", but it's less reliable (sometimes you really need to look under the hood to fix some specific problems).

I generally find the look and feel of GNOME more elegant, and that of KDE more nerdy, but that's just my opinion.

I sometimes like GNOME, other times prefer KDE, and I end up switching from one to the other whenever one of them announces a new improvement, which is quite often.

But surprisingly I found very little information about how to switch from one to the other... finally, after looking here and there, I found out. It's simple, as these things are once you know them. Here's what you need to do:

• If you are under Ubuntu (GNOME) and want to switch to Kubuntu, simply install kubuntu-desktop by using Synaptics or your favourite package manager
• If you are under Kubuntu (KDE) and want to switch to Ubuntu... well, simply install ubuntu-desktop by using adept_manager or your favourite package manager

KDM and GNOME have their own display managers, and oddly enough KDM does work fine under GNOME's display manager, and vice-versa. So there's no real need to change display managers unless you want to. To do this, after installing kubuntu_desktop or ubuntu_desktop simply edit the file /etc/X11/default-display-manager so that it has the following contents:

• /usr/sbin/gdm to set GDM, that is, the Gnome display manager
• /usr/bin/kdm to set KDM, the KDE display manager
• /usr/lib/kde4/bin/kdm to set KDM for KDE4, the new version of KDE which is still under experimentation. To use KDE4 you will need to install the package kubuntu-kde4-desktop (you guessed right)

I like the look and feel of GNOME but I want the flexibility of many of the programs associated with KDE (such as digikam for managing photos, or amarok for playing music). The good thing is that these programs also run under GNOME so it is actually possible to get the best of both worlds.