Kubuntu is a free, user-friendly Linux distribution based on KDE's desktop software and on the Ubuntu operating system. It has a biannual release cycle. Besides providing an up-to-date version of the KDE desktop at the time of the release, the project also releases updated KDE packages throughout the lifetime of each release. Kubuntu is an official flavour of the Ubuntu operating system which uses the KDE Plasma Desktop instead of the Unity graphical environment. As part of the Ubuntu project, Kubuntu uses the same underlying systems. Every package in Kubuntu shares the same repositories as Ubuntu, and it is released regularly on the same schedule as Ubuntu. Kubuntu was sponsored by Canonical Ltd. until 2012, and then directly by Blue Systems. Now employees of Blue Systems contribute upstream, to KDE and Debian, and Kubuntu development is led by community contributors. During the changeover, Kubuntu retained the use of Ubuntu project servers and existing developers.