The Xfce desktop environment team has announced the development of a new composite server Xfwl4 that utilizes the Wayland protocol. This new project, Xfwl4, is being built from scratch in the Rust language, using the Smithay library, instead of using the code base of the current xfwm4 window manager. The expected first test release of Xfwl4 is set for mid-2026, and its code is distributed under the GPLv3 license.
Xfwl4 is aiming to incorporate all the functionality present in xfwm4, including the utilization of existing xfconf settings and the configuration interface. However, it is being designed to work with Wayland instead of X11. Advanced features of Xfwl4 will include a significant restructuring of session launch logic, the implementation of the Wayland protocol xdg-session-management, and support for launching X11 applications using XWayland.
The decision to develop a new composite server stemmed from the challenges faced in trying to implement simultaneous support for X11 and Wayland in the current xfwm4 window manager architecture. The tight integration of the X11 protocol in xfwm4 made it difficult to separate window management logic from X11-specifics. Gradually adding Wayland support to xfwm4 was deemed impractical due to potential stability issues and increased risk of introducing new errors during refactoring.
Xfwl4 is being built on top of the Smithay library, which offers implementations of most official Wayland protocol extensions, as well as the wlroots and KDE protocols. This library allows developers to intervene in low-level system operations, adapt graphics output methods, work with input devices, Wayland protocols, and customize desktop building tasks according to their requirements. Furthermore, the choice of Rust language for Xfwl4 development aims to reduce memory-related errors and minimize crashes.