Ubuntu is a free and open-source Linux operating system based on Debian GNU/Linux. It is named after the African philosophy of Ubuntu, which means "humanity towards others". Users are encouraged to use, improve, and share Ubuntu freely. Canonical releases new versions of Ubuntu every six months, with long-term support releases every two years; the latest versions are 11.04 Natty Narwhal and 10.04 Lucid Lynx.