Mutter is a GObject-based library for creating compositing window managers. Compositors that wish to use Mutter must implement a subclass of #MetaPlugin and register it with meta_plugin_manager_set_plugin_type() before calling meta_init() but after g_type_init(). #MetaPlugin provides virtual functions that allow to override default behavior in the window management code, such as the effect to perform when a window is created or when switching workspaces.