Mutter is a Wayland display server and X11 window manager and compositor library.

When used as a Wayland display server, it runs on top of KMS and libinput. It implements the compositor side of the Wayland core protocol as well as various protocol extensions. It also has functionality related to running X11 applications using Xwayland. When used on top of Xorg it acts as a X11 window manager and compositing manager. It contains functionality related to, among other things, window management, window compositing, focus tracking, workspace management, keybindings and monitor configuration.

Mutter is used by, for example, GNOME Shell, the GNOME core user interface, and by Gala, elementary OS’s window manager. It can also be run standalone, using the command “mutter”, but just running plain mutter is only intended for debugging purposes.

## Contributing

Mutter is Free Software and is developed in the open.

To contribute, open merge requests at `https://gitlab.gnome.org/GNOME/mutter`.

It can be useful to first look at the GNOME Handbook and the documentation and API references below first.

## Documentation

- Coding style and conventions
- Git conventions
- Code overview
- Building and Running
- Debugging
- Monitor configuration

## API Reference

- ### Meta

  The display server and window manager library. Contains a X11 window manager and compositing manager implementation, as well as a Wayland display server implementation.

- ### Clutter

  Compositing toolkit, containing an actor and render node based scene graph, and has features such as input event routing, transformation and animation. Handles compositing, both Wayland surfaces, X11 windows, and is the basis of the UI toolkit implemented by GNOME Shell.

- ### Cogl

  Hardware acceleration pipeline abstraction layer. Handles things like allocating framebuffer, allocating, importing and drawing textures, internally using OpenGL.

- ### Mtk

  The Meta Toolkit containing utilities shared by other parts of mutter.

## Useful Links

- Source Code
- Code Coverage Report
- Development blog