Comment 0 for bug 1203207

mir is the new display server planned for introduction into 13.10
unity-system-compositor is a component needed for the xmir configuration to work and leverage mir for 13.10

These components have been available and are currently being tested as part of the ppa:mir-team/system-compositor-testing
there are no major bugs and its introduction is expected not to interfere with saucy.
the xmir functionality being introduced will allow the X to continue in standalone mode if there is a failure.