Running programs natively under Wayland

If your toolkit/library supports this, you can have your apps run natively (without Xwayland) by setting some environment variables (you can add them to your launcher script or a session file if you're using a display manager).

You can disable Xwayland (X clients under Wayland) support by specifying xwayland disable in your Sway config.

GTK3

Wayland will be selected by default. Do not set GDK_BACKEND, it will break apps (e.g. Chromium and Electron).

Experimental Wayland support in Firefox can be enabled with MOZ_ENABLE_WAYLAND=1.

Qt5

Wayland is used by default if XDG_SESSION_TYPE=wayland is set (ie. if you use a display manager). If not:

QT_QPA_PLATFORM=wayland-egl

To use your monitor's DPI instead of the default of 96 DPI:

QT_WAYLAND_FORCE_DPI=physical

Older versions of Qt always show window decorations. To hide them:

QT_WAYLAND_DISABLE_WINDOWDECORATION=1

NOTE: You might need a package, such as qtwayland5 for Ubuntu or qt5-wayland for Arch Linux, to enable Wayland support.

Elementary/EFL

ECORE_EVAS_ENGINE=wayland_egl
ELM_ENGINE=wayland_egl

You could set them to wayland_shm instead, if you want to use software rendering.

SDL

SDL_VIDEODRIVER=wayland

GLFW

Wayland needs to be selected at compile-time. Arch users can install glfw-wayland.

Java under Xwayland

Some Java AWT applications would not display properly unless you set the following.

_JAVA_AWT_WM_NONREPARENTING=1