GNOME Mutter 3.25.92 Adds Built-In Screencast / Remote Desktop Capabilities
First and arguably most exciting is screencast and remote desktop support added to GNOME itself. Separate from screen casting/sharing at the X11 level or baked into Wayland itself, the Mutter compositor has introduced screensharing support itself. This is tied into two new D-Bus APIs (org.gnome.Mutter.ScreenCast and org.gnome.Mutter.RemoteDesktop). These interfaces can be tied into PipeWire streams while remote desktop interfaces can be used for injecting input events.
PipeWire as a reminder could replace PulseAudio and serve both the audio/video needs of the modern Linux desktop.
For making use of the latest Mutter code, one application implementing the new Mutter screen broadcasting APIs via PipeWire is the (currently basic) gnome-remote-desktop program. Jonas Ådahl of Red Hat has been working on this GNOME-catered windowing system independent remote desktop capability for the past few months.
Semi-related to this is support in Mutter for now running when there are no physical monitors attached.
This and other work can be found in the just-released Mutter 3.25.92 ahead of the GNOME 3.26 stable debut later this month.