Hello Linux Geeksters. As you may know, Canonical has decided to replace the X.org graphical server with Mir, their own display server, on Ubuntu 13.10 Saucy Salamander and also use it on Ubuntu Touch.
For now, the Mir display server has support only for the open-source graphical drivers, developed by Intel, Nouveau and Radeon. The users having video cards with proprietary drivers will still use the X.org display server, even though Ubuntu 13.10 Saucy Salamander will use Mir / XMir as default.
Because Mir and XMir have been added to the default repositories of Ubuntu 13.10 Saucy Salamander, they can be easily installed for testing purposes.
To install Mir on Ubuntu 13.10 Saucy Salamander, update and upgrade the system to its latest version and install the package unity-system-compositor, like this:
$ sudo apt-get update
$ sudo apt-get dist-upgrade
$ sudo apt-get install unity-system-compositor
Note: Mir has been released for testing purposes only (it is highly unstable), to help the users see its magic.