Lubuntu is a fast and lightweight operating system with a clean and easy-to-use user interface. It is a Linux system, that uses the minimal desktop LXDE/LXQT, and a selection of light applications. Because of this, Lubuntu has very low hardware requirements. Lubuntu was founded by Mario Behling and has been grown for many years by Julien Lavergne.

Lubuntu Linux is a project that is intended to lead to an official derivative of the Ubuntu operating system that is lighter, less resource hungry and more energy-efficient, using the LXQt desktop environment.

The LXQt desktop uses the Openbox window manager and is intended to be a low system requirement, low RAM environment for netbooks, mobile devices and older PCs.

In February 2009, Mark Shuttleworth of Ubuntu invited the LXDE project to become a self-maintained project within the Ubuntu community, with the aim of leading to a dedicated new official Ubuntu derivative to be called Lubuntu. The project also established an official Ubuntu wiki project page, also under Behling's management, that includes listings of applications, packages, and components.