In the future, could Mir function as a drop-in replacement for KWin?

The KWin/Wayland page on the KDE Community Wiki includes a section with the following heading: Why not a new Compositor?

The page recites multiple reasons for not implementing a new Wayland compositor from scratch to replace KWin. Among those recited reasons is the following:

Another reason is that the KWin development team does not have the manpower to maintain an independent X11 window manager and a Wayland compositor. Starting a new Wayland compositor would mean to stop the work on the X11 window manager, which would be a bad move as we cannot know yet whether Wayland will succeed and will be supported on all hardware.

Granted, the situation may have changed since the linked page was originally posted. But I sense that “manpower” remains among the reasons that KWin hasn’t been replaced.

Question: Comparing the features offered by Mir to the features offered by KWin, would it be feasible for Mir to function as a drop-in replacement for KWin? And if not feasible now, do you expect it to be feasible in the future?

To be clear, I’m not requesting that the Mir team add features that would allow Mir to function as a drop-in replacement for KWin. Rather, I’m just curious if this is among your goals (and would be pleased if it is).

The situation has changed a lot. The page you reference appears to have been written around 2015, it refers to decision taken a long time ago to extend KWin to incorporate Wayland support instead supporting mirclient. Wayland support has now been implemented in KWin for some time. It is a moot point whether they avoided the need to abandon mirclient or if a different choice by KDE might have avoided mirclient being deprecated.

I don’t have a detailed knowledge of the KWin features used by KDE, but Mir is intended to allow such things to be written. For example, there’s a project based on Mir that provides MATE with a replacement for their Mutter fork: Mirco. (This is only a part of the MATE transition to Wayland which requires a lot more than a Wayland compositor - the shell components also need to migrate from X11.)

However, while it should be possible, I don’t foresee either the Mir project or the KDE project spending time making a drop in replacement for KWin.

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