Canonical LTD maintains two discrete versions of Unity which are almost indistinguishable from a visual standpoint but very different on the technical level. Unity is written as a plugin for Compiz and is written in the programming languages C++ and Vala and is utilizing an uncommon OpenGL toolkit called Nux. Being a plugin for Compiz gives Unity GPU-accelerated performance on compatible systems.Unity 2D is a set of individual applications. They are written in the GUI building language QML from the widespread Qt framework. By default Unity 2D uses the non-compositing Metacity window manager but can also use accelerated window managers like Compiz or KWin.