As many of you will know, the Mir team had two core goals for the Ubuntu 13.10 cycle:

1. Deliver Mir + XMir + Unity 7 on the desktop for those cards that supported it, and fall back to X for those that don’t.
2. Deliver a native Mir + Unity 8 running on Ubuntu Touch images and devices.

Unfortunately, due to some outstanding technical difficulties, we can only achieve the latter of these two goals.

While we are on track to successfully deliver Mir for Ubuntu on smartphones, we are unfortunately not going to be able to deliver Mir + XMir + Unity 7 as the default experience on the desktop.

Mir has made tremendous progress and is currently available on the Ubuntu archive for use, but there are still some outstanding quality issues that we want to resolve before we feel comfortable turning it on by default. Many of these issues live in the XMir part of the stack, which provides the integration between the X server and the underlying Mir system compositor. More specifically, the multi-monitor support in XMir is working, but not to the extend we'd like to see it for all of our users. The core of Mir is working reliable, but with XMir being a key component for our 13.10 goals, we didn’t want to compromise overall Ubuntu quality by shipping it.

Mir & XMir are available from the archive as an optional configuration, but XMir won't be part of the default configuration.

I know many of you have been curious about the progress of discussions with GPU manufacturers about Mir support, and while those conversations are under NDA, I can assure you they are progressing forward.

We have compiled a Q&A which can be found at https://wiki.ubuntu.com/Mir/13.10/NoDefaultQ%26A

If you have any further queries, please feel free to reach out to me or my team, and feel free to discuss this in more detail either here or on mir-devel (https://lists.ubuntu.com/archives/mir-devel/).