Edit: Due to the fact that this article is old, the installation instructions may not work anymore. In order to successfully install the latest version of KDE Plasma, please access the KDE tag and open the latest article (the one on top).
The latest installation instructions for KDE Plasma
Hello Linux Geeksters.The KDE 4.11.5 desktop environment has been released a while ago. Among others, it comes with over 65 bug-fixes, improved Kontact PIM (Personal Information Management) suite, updated versions of Okular, KWin, Konqueror and a the new Umbrello UML unitility. For more information, see the changelog.
In this article I will show you how to install KDE 4.11.5 on Ubuntu 13.10 Saucy Salamander, Ubuntu 13.04 Raring Ringtail, Ubuntu 12.10 Quantal Quetzal and Ubuntu 12.04 Precise Pangolin.
It will be soon added to the Kubuntu Backports Repository, so installing KDE 4.11.5 on the latest versions of Ubuntu is easy. You can either add the ppa to your system, update the local repository index and install the kubuntu-desktop package:
$ sudo add-apt-repository ppa:kubuntu-ppa/backports
$ sudo apt-get update
$ sudo apt-get install kubuntu-desktop
Or just add the repository to your system and perform a normal system upgrade:
$ sudo add-apt-repository ppa:kubuntu-ppa/backports
$ sudo apt-get update
$ sudo apt-get upgrade