Black Lab Linux (formerly OS4 OpenLinux) is a user-friendly, commercial desktop and server Linux distribution based on Ubuntu. Some of its most interesting features include support for popular browser plugins, addition of packages for multimedia production, content creation and software development, and an innovative desktop layout based on GNOME Shell. Separate editions with KDE and Xfce desktops are also available. The company behind the distribution also sells a desktop mini-system with Black Lab Linux pre-installed.