Kubuntu is an official derivative of the Ubuntu operating system using the KDE Software Compilation instead of the GNOME graphical environment. It is part of the Ubuntu project and uses the same underlying system. It is possible to run both the KDE desktop (kubuntu-desktop) as well as the Gnome desktop (ubuntu-desktop) interchangeably on the same machine. Every package in Kubuntu shares the same repositories as Ubuntu. It is released regularly on the same schedule as Ubuntu.
"Kubuntu", pronounced /kuːˈbuːntuː/ koo-BOON-too, means "towards humanity" in Bemba, and is derived from ubuntu ("humanity"). The K at the beginning represents the KDE community on whose desktop/applications Kubuntu runs. By coincidence, Kubuntu also means "free" in Kirundi.
Differences from Ubuntu
A regular installation of Ubuntu uses the GNOME desktop, GTK+/GNOME applications and packages (e.g. Evolution), and GTK+/GNOME-based admin tools (e.g. Synaptic Package Manager). In contrast, a regular installation of Kubuntu uses KDE's plasma desktop, KDE/Qt applications and packages (e.g. Kontact), and KDE/Qt admin tools (e.g. KPackageKit). Nevertheless, Kubuntu users can install and use any GNOME/GTK-based package that is available in the Ubuntu repositories, and Ubuntu/GNOME users similarly can install and use any KDE/Qt-based package. One may install Ubuntu and then add the KDE Software Compilation, for example, or can install the entire Kubuntu desktop 'metapackage' on top of Ubuntu. (There is a slight disadvantage to installing and using both the GNOME desktop and the KDE plasma desktop, however, namely the increased diskspace and memory requirements of running both GTK/GNOME and Qt/KDE.)
The Kubuntu desktop is fully customizable. 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. 3-D effects are available in the standard KDE SC 4 installation.
Ubuntu, which uses the Gnome desktop, follows the GNOME desktop release cycles. It was created first.
Mark Shuttleworth in an interview shortly thereafter stated:
I believe that the KDE community does phenomenal work, and having a community-driven distribution to showcase that work will help attract users and developers to the project. Our overall goal in the Ubuntu project is to further the adoption of free software on the desktop and the server, and we recognise that KDE is an essential part of the mix of desktop environments that allows people to find the best environment for their needs.
The Kubuntu team then released their first edition, Hoary Hedgehog, on April 8th, 2005.
The minimum system requirements for a desktop installation are a 300 MHz x86 processor, 64 MB of RAM, 4 GB of hard drive space, and a video card which supports VGA at 640x480 resolution. The recommended system requirements for the desktop installation are a 700 MHz x86 processor, 384 MB of RAM, 8 GB of hard drive space, and a video card which supports VGA at 1024×768 resolution.