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.
Wayland should be selected by default. If not, this can be overridden on a per-app basis by setting:
# Do not set this globally
GDK_BACKEND=wayland
CLUTTER_BACKEND=wayland
Setting GDK_BACKEND=wayland however can still lead to startup crashes with some applications, e.g. chromium (as of Feb. 2019) and electron. For this reason GDK_BACKEND should not be set globally.
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
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_VIDEODRIVER=wayland
Wayland needs to be selected at compile-time. Arch users can install glfw-wayland.
Some Java AWT applications would not display properly unless you set the following.
_JAVA_AWT_WM_NONREPARENTING=1
