Prominent new features of GTK+ 3.22, which, as you can see from Matthias Clasen’s quote above, will be a long-term supported release, include support for XDG-Shell version 6 and drawing tables to the Wayland backend, new gesture API (Application Programming Interface) for tablet support implemented as GtkPadController, as well as GLES (OpenGL for Embedded Systems) support for the GdkGLContext widget. Moreover, there’s now a new API implemented in the GdkMonitor widget to allow richer information to be parsed about connected outputs, new max-content-width and max-content-height properties have been added to the GtkScrolledWindow widget for improved sizing behavior, and it looks like portals are now being transparently used by various GTK+ APIs when they’re in a Flatpak sandbox.