What are pros and cons of Mir vs Wayland?

[behrangsa]

Why Canonical decided to build their own display server rather than using Wayland?

I think at the end of the day, even if Mir ends up lacking decent driver support, it is not gonna be a big deal, because there's always XFCE, KDE, etc. and it seems like they are gonna adopt Wayland anyway. So one can abandon Ubuntu and use, say, KDE Neon.

But what did Mir lack that forced Canonical to implement their own display server?

Thanks,
Behrang

[behrangsa]

Well, I think this Wikipedia piece shed some light about why Canonical decided to go the Mir way.

Are these claims still true and enough to justify abandoning Wayland:

our evaluation of the protocol definition revealed that the Wayland protocol does not meet our requirements. First, we are aiming for a more extensible input event handling that takes future developments like 3D input devices (e.g. Leap Motion) into account...With respect to mobile use-cases, we think that the handling of input methods should be reflected in the display server protocol, too. As another example, we consider the shell integration parts of the protocol as privileged and we'd rather avoid having any sort of shell behavior defined in the client facing protocol.

In particular:

• Would Wayland eventually evolve their protocol to support "more extensible event handling devices"?
• What about mobile use-cases? I had a chat with Jonathan Riddell and asked him if Wayland is suitable for tablet and mobile devices and he replied "Very much, it's what we use in plasma mobile", so it seems Canonical's criticism of Wayland regarding mobile devices is also not true.
• What about the "shell integration parts"?

Thanks,
Behrang