# Part I. Overview

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.