I’m not sure if/how Mir can help with this, but…
The state of Global Menu support is inconsistent (to be charitable) among various DEs. For example, in my experience, Global Menus work pretty well on Plasma with some Qt apps, but not so much with GTK apps. MATE seems to offer better Global Menu support for a greater variety of apps, but support is still inconsistent. So, could Mir offer some sort of back-end that would allow for better consistency?
Also, more and more GNOME applications are using CSD. Some apps using CSD provide optional FEV menus that can be used in conjunction with Global Menus, but many don’t. I realize that this is highly unlikely, but I wonder, could Mir offer some sort of back-end that would allow displaying a GTK apps’s full CSD (not just an FEV menu, which some devs seem to eschew) outside of the application’s window, such as in a top bar?
I guess what I’m after is a back-end that could support a truly universal Global Menu, that would work with Qt apps and GTK apps, including GTK apps that use CSD exclusively.
And of course, if such a back-end also allowed for specifying under what conditions CSD/menus would be displayed outside the window (such as “only for maximized windows” etc.), but otherwise displayed in the the title bar area (like Unity’s LIM does), that would be amazing.
Sorry for bringing up a hot button issue, but…
If not already supported, please consider supporting EGLStreams for Wayland. Also, hopefully Mir’s XWayland will play nicely with X11 Server 1.20, which is anticipated to support EGLStreams for XWayland.