Canonical Releases Mir 1.2 For Fostering Mir-Based Shells With Extra Wayland Extensions
Mir 1.2 comes with a new libmirwayland-dev package that is their first hit at their APIs for enabling Mir-based shells to support their own Wayland extensions. Mir 1.2 also brings additions to the MirAL APIs abstraction layer for registering the custom extensions and a new MinimalWindowManager class that provides a default window management policy.
On the X11 side, there is support now for firing up XWayland on-demand. Ubuntu developers are also hoping to get X11/XWayland support for Mir out of the "experimental" box during the Ubuntu 19.10 cycle.
There are also different bug fixes, support for multiple outputs in Mir-on-X, initial support for the XDG-Output protocol, and other additions making up Mir 1.2.
More details on Mir 1.2 via the release announcement.