Kubuntu Linux 12.04.1 LTS (64-bit)

Kubuntu is a GNU/Linux operating system built by a worldwide team of expert developers. It contains all the applications you need: a web browser, an office suite, media apps, an instant messaging client and many more. It's based on KDE Plasma desktop and KDE software. This is a Long Term Support release.

Kubuntu is an official derivative of the Ubuntu operating system using the KDE Plasma Desktop instead of the Unity graphical environment. Blue Systems took over as sponsor from Canonical, and Kubuntu will retain use of Ubuntu project servers.[3] It is part of the Ubuntu project and uses the same underlying system. It is possible to install both the KDE Plasma Desktop (kubuntu-desktop) as well as the Unity desktop (ubuntu-desktop) on the same machine. Every package in Kubuntu shares the same repositories as Ubuntu.[4] It is released regularly on the same schedule as Ubuntu

Kubuntu's Plasma Desktop is fully customizable without extra tools or configuration file editing. Originally designed to ease transition for users from other operating systems (such as Microsoft Windows) by allowing a similar desktop layout, the KDE Plasma Desktop incorporates widget-centric modularity that allows the user to incorporate function similar to all other operating systems and also create new functionality not found in other operating system desktops. Desktop effects are integrated in the standard KWin installation, and enabled by default if supported.

Because Ubuntu and Kubuntu use the same sources, any application intended for one is installable and runnable on the other. Consequently, it is very common to see situations such as Firefox running on Kubuntu, or K3b running on Ubuntu.