This is primarily a bug fix release for all supported platforms but it also adds libdecor support for Wayland. This provides better window decorations in some desktop environments, notably GNOME.
With this release GLFW should be fully usable on Wayland, although there are still some issues left to resolve.
This release and future 3.3.x patch releases are based on the 3.3-stable branch.
See the version history for a complete list of changes.