For Bookworm, we are using a compositor called Wayfire. This uses a standard Wayland library called wlroots, which is used by several modern Wayland compositors. And because Wayfire works a lot better as a Wayland compositor on Raspberry Pi than Mutter did, Wayland is now the default mode of operation for the desktop. (With one caveat - for now, Wayland is only the default on Raspberry Pi 4 and 5. The performance of Wayfire on earlier platforms is still being optimised, so for now they will continue to run the old X11 display server and the Openbox window manager, but at some point these platforms will also be switched to Wayfire.) If you boot Raspberry Pi OS on a Pi 4 or 5, you will now get a Wayfire desktop.
Download Raspberry Pi OS