The goal to enable XMir by default for supported graphics cards in Ubuntu 13.10 has been pushed back.

Developer Olli Ries announced the setback on the Ubuntu Development mailing list Tuesday night, citing “outstanding technical difficulties” as the impetus for pushing back XMir by default for compatible hardware.

XMir acts as a compatibility layer between Mir – Canonical’s display server alternative to the ageing X server – and applications that only support X. Similarly, Wayland – the other popular X protocol alternative – and its reference implementation Weston make use of xwayland to handle applications that only support X.

Setbacks

“…we didn’t want to compromise overall Ubuntu quality by shipping it.”

The initial decision to enable Mir and XMir by default in 13.10 was made back in June. At the time, the goal was to ultimately ship Mir as the only default by 14.04 LTS, using 13.10 to thoroughly test Mir before shipping in the upcoming LTS release.

Though Ries notes that the “core of Mir is working reliabl[y]”, the team were not satisfied with how this compatibility layer handled multi-monitor setups.

Earlier last month, Intel also removed XMir support from its Xorg driver, but the Q&A for this latest setback explicitly mentions that this decision is not related to the Intel incident. Indeed, Intel cited more political than technical reasons for their removal of XMir support.

What This Means For You

For Ubuntu Touch, Mir is still set to be enabled by default – though work is still ongoing.

For Ubuntu on the desktop, Mir and XMir will still be available to install and test from the repos whilst the team continue fine tuning multi-monitor behaviour and other issues.

Announcement on the Mailing List

Q&A About the Decision