KDE is preferred desktop by large Linux user base and Canonical acknowledge importance of KDE therefore they have separate edition named as KUbuntu. KDE applications are based upon Qt Framework and many open-source applications make use of Qt Framework which works natively in KDE.
If you don’t like Unity Interface and installed GNOME-Shell and didn’t liked it either and don’t want to download KUbuntu separately then this tutorial is for you. KDE is present in Ubuntu repositories and can be easily installed. You should try KDE desktop if you are disappointed by Unity and GNOME-Shell. KDE is featured filled desktop with very beautiful look and feel. It allows you to make a desktop according to your needs by installing widgets according to your interests and customizing themes of your KDE desktop. For deployment and administration KDE performs well with the help of KDE authorization framework.
Click the following button to install KDE Plasma Desktop on your existing Ubuntu 11.10 installation.
For full set of KDE packages which includes additional applications/packages click following link.
When installation is complete restart your computer and login by selecting KDE as your session in LightDM.
Note: Updated for Ubuntu 12.04 LTS Precise Pangolin on 27th April, 2012